diff --git a/crc/api/file.py b/crc/api/file.py
index 733dcd34..07ced388 100644
--- a/crc/api/file.py
+++ b/crc/api/file.py
@@ -1,30 +1,39 @@
 import io
+from typing import List
 
 import connexion
 from flask import send_file
 
 from crc import session
 from crc.api.common import ApiError
-from crc.models.file import FileModelSchema, FileModel
+from crc.models.file import FileSchema, FileModel, File, FileModelSchema
 from crc.models.workflow import WorkflowSpecModel
 from crc.services.file_service import FileService
 
 
+def to_file_api(file_model):
+    """Converts a FileModel object to something we can return via the aip"""
+    return File.from_models(file_model, FileService.get_file_data(file_model.id))
+
+
 def get_files(workflow_spec_id=None, workflow_id=None, form_field_key=None):
     if all(v is None for v in [workflow_spec_id, workflow_id, form_field_key]):
         raise ApiError('missing_parameter',
                        'Please specify either a workflow_spec_id or a '
                        'workflow_id with an optional form_field_key')
 
-    results = FileService.get_files(workflow_spec_id=workflow_spec_id,
-                                    workflow_id=workflow_id,
-                                    irb_doc_code=form_field_key)
-    return FileModelSchema(many=True).dump(results)
+    file_models = FileService.get_files(workflow_spec_id=workflow_spec_id,
+                                        workflow_id=workflow_id,
+                                        irb_doc_code=form_field_key)
+
+    files = (to_file_api(model) for model in file_models)
+    return FileSchema(many=True).dump(files)
 
 
 def get_reference_files():
     results = FileService.get_files(is_reference=True)
-    return FileModelSchema(many=True).dump(results)
+    files = (to_file_api(model) for model in results)
+    return FileSchema(many=True).dump(files)
 
 
 def add_file(workflow_spec_id=None, workflow_id=None, form_field_key=None):
@@ -43,7 +52,7 @@ def add_file(workflow_spec_id=None, workflow_id=None, form_field_key=None):
     else:
         raise ApiError("invalid_file", "You must supply either a workflow spec id or a workflow_id and form_field_key.")
 
-    return FileModelSchema().dump(file_model)
+    return FileSchema().dump(to_file_api(file_model))
 
 
 def get_reference_file(name):
@@ -78,7 +87,7 @@ def set_reference_file(name):
         file_model = file_models[0]
         FileService.update_file(file_models[0], file.stream.read(), file.content_type)
 
-    return FileModelSchema().dump(file_model)
+    return FileSchema().dump(to_file_api(file_model))
 
 
 def update_file_data(file_id):
@@ -87,7 +96,7 @@ def update_file_data(file_id):
     if file_model is None:
         raise ApiError('no_such_file', 'The file id you provided does not exist')
     file_model = FileService.update_file(file_model, file.stream.read(), file.content_type)
-    return FileModelSchema().dump(file_model)
+    return FileSchema().dump(to_file_api(file_model))
 
 
 def get_file_data(file_id, version=None):
@@ -99,7 +108,7 @@ def get_file_data(file_id, version=None):
         attachment_filename=file_data.file_model.name,
         mimetype=file_data.file_model.content_type,
         cache_timeout=-1,  # Don't cache these files on the browser.
-        last_modified=file_data.last_updated
+        last_modified=file_data.date_created
     )
 
 
@@ -107,7 +116,7 @@ def get_file_info(file_id):
     file_model = session.query(FileModel).filter_by(id=file_id).with_for_update().first()
     if file_model is None:
         raise ApiError('no_such_file', 'The file id you provided does not exist', status_code=404)
-    return FileModelSchema().dump(file_model)
+    return FileSchema().dump(to_file_api(file_model))
 
 
 def update_file_info(file_id, body):
@@ -122,7 +131,7 @@ def update_file_info(file_id, body):
     file_model = FileModelSchema().load(body, session=session)
     session.add(file_model)
     session.commit()
-    return FileModelSchema().dump(file_model)
+    return FileSchema().dump(to_file_api(file_model))
 
 
 def delete_file(file_id):
diff --git a/crc/api/workflow.py b/crc/api/workflow.py
index f67cc12f..9154652a 100644
--- a/crc/api/workflow.py
+++ b/crc/api/workflow.py
@@ -118,8 +118,8 @@ def __get_workflow_api_model(processor: WorkflowProcessor, next_task = None):
         next_task=None,
         navigation=navigation,
         workflow_spec_id=processor.workflow_spec_id,
-        spec_version=processor.get_spec_version(),
-        is_latest_spec=processor.get_spec_version() == processor.get_latest_version_string(processor.workflow_spec_id),
+        spec_version=processor.get_version_string(),
+        is_latest_spec=processor.is_latest_spec,
         total_tasks=processor.workflow_model.total_tasks,
         completed_tasks=processor.workflow_model.completed_tasks,
         last_updated=processor.workflow_model.last_updated
diff --git a/crc/models/approval.py b/crc/models/approval.py
index 8591f3df..7fad2a43 100644
--- a/crc/models/approval.py
+++ b/crc/models/approval.py
@@ -4,7 +4,7 @@ from marshmallow import INCLUDE
 from sqlalchemy import func
 
 from crc import db, ma
-from crc.models.file import FileModel
+from crc.models.file import FileModel, FileDataModel
 from crc.models.study import StudyModel
 from crc.models.workflow import WorkflowModel
 
@@ -17,13 +17,11 @@ class ApprovalStatus(enum.Enum):
 
 
 class ApprovalFile(db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    file_id = db.Column(db.Integer, db.ForeignKey(FileModel.id), nullable=False)
-    approval_id = db.Column(db.Integer, db.ForeignKey("approval.id"), nullable=False)
-    file_version = db.Column(db.Integer, nullable=False)
+    file_data_id = db.Column(db.Integer, db.ForeignKey(FileDataModel.id), primary_key=True)
+    approval_id = db.Column(db.Integer, db.ForeignKey("approval.id"), primary_key=True)
 
     approval = db.relationship("ApprovalModel")
-    file = db.relationship(FileModel)
+    file_data = db.relationship(FileDataModel)
 
 
 class ApprovalModel(db.Model):
@@ -38,9 +36,9 @@ class ApprovalModel(db.Model):
     message = db.Column(db.String)
     date_created = db.Column(db.DateTime(timezone=True), default=func.now())
     version = db.Column(db.Integer) # Incremented integer, so 1,2,3 as requests are made.
-    workflow_hash = db.Column(db.String) # A hash of the workflow at the moment the approval was created.
-
-    approval_files = db.relationship(ApprovalFile, back_populates="approval")
+    approval_files = db.relationship(ApprovalFile, back_populates="approval",
+                                     cascade="all, delete, delete-orphan",
+                                     order_by=ApprovalFile.file_data_id)
 
 
 class Approval(object):
@@ -57,7 +55,6 @@ class Approval(object):
         instance.message = model.message
         instance.date_created = model.date_created
         instance.version = model.version
-        instance.workflow_hash = model.workflow_hash
         instance.title = ''
         if model.study:
             instance.title = model.study.title
diff --git a/crc/models/file.py b/crc/models/file.py
index c351d2a7..e779f52a 100644
--- a/crc/models/file.py
+++ b/crc/models/file.py
@@ -1,6 +1,7 @@
 import enum
 from typing import cast
 
+from marshmallow import INCLUDE, EXCLUDE
 from marshmallow_enum import EnumField
 from marshmallow_sqlalchemy import SQLAlchemyAutoSchema
 from sqlalchemy import func, Index
@@ -10,7 +11,7 @@ from crc import db, ma
 
 
 class FileType(enum.Enum):
-    bpmn = "bpmm"
+    bpmn = "bpmn"
     csv = 'csv'
     dmn = "dmn"
     doc = "doc"
@@ -55,15 +56,16 @@ CONTENT_TYPES = {
     "zip": "application/zip"
 }
 
+
 class FileDataModel(db.Model):
     __tablename__ = 'file_data'
     id = db.Column(db.Integer, primary_key=True)
     md5_hash = db.Column(UUID(as_uuid=True), unique=False, nullable=False)
     data = db.Column(db.LargeBinary)
     version = db.Column(db.Integer, default=0)
-    last_updated = db.Column(db.DateTime(timezone=True), default=func.now())
+    date_created = db.Column(db.DateTime(timezone=True), default=func.now())
     file_model_id = db.Column(db.Integer, db.ForeignKey('file.id'))
-    file_model = db.relationship("FileModel")
+    file_model = db.relationship("FileModel", foreign_keys=[file_model_id])
 
 
 class FileModel(db.Model):
@@ -79,9 +81,30 @@ class FileModel(db.Model):
     workflow_spec_id = db.Column(db.String, db.ForeignKey('workflow_spec.id'), nullable=True)
     workflow_id = db.Column(db.Integer, db.ForeignKey('workflow.id'), nullable=True)
     irb_doc_code = db.Column(db.String, nullable=True) # Code reference to the irb_documents.xlsx reference file.
-    latest_version = db.Column(db.Integer, default=0)
 
 
+class File(object):
+    @classmethod
+    def from_models(cls, model: FileModel, data_model: FileDataModel):
+        instance = cls()
+        instance.id = model.id
+        instance.name = model.name
+        instance.is_status = model.is_status
+        instance.is_reference = model.is_reference
+        instance.content_type = model.content_type
+        instance.primary = model.primary
+        instance.primary_process_id = model.primary_process_id
+        instance.workflow_spec_id = model.workflow_spec_id
+        instance.workflow_id = model.workflow_id
+        instance.irb_doc_code = model.irb_doc_code
+        instance.type = model.type
+        if data_model:
+            instance.last_modified = data_model.date_created
+            instance.latest_version = data_model.version
+        else:
+            instance.last_modified = None
+            instance.latest_version = None
+        return instance
 
 class FileModelSchema(SQLAlchemyAutoSchema):
     class Meta:
@@ -89,6 +112,17 @@ class FileModelSchema(SQLAlchemyAutoSchema):
         load_instance = True
         include_relationships = True
         include_fk = True  # Includes foreign keys
+        unknown = EXCLUDE
+    type = EnumField(FileType)
+
+
+class FileSchema(ma.Schema):
+    class Meta:
+        model = File
+        fields = ["id", "name", "is_status", "is_reference", "content_type",
+                  "primary", "primary_process_id", "workflow_spec_id", "workflow_id",
+                  "irb_doc_code", "last_modified", "latest_version", "type"]
+        unknown = INCLUDE
     type = EnumField(FileType)
 
 
diff --git a/crc/models/study.py b/crc/models/study.py
index 283196e2..38bd2f3b 100644
--- a/crc/models/study.py
+++ b/crc/models/study.py
@@ -64,7 +64,7 @@ class WorkflowMetadata(object):
             name=workflow.workflow_spec.name,
             display_name=workflow.workflow_spec.display_name,
             description=workflow.workflow_spec.description,
-            spec_version=workflow.spec_version,
+            spec_version=workflow.spec_version(),
             category_id=workflow.workflow_spec.category_id,
             state=WorkflowState.optional,
             status=workflow.status,
diff --git a/crc/models/workflow.py b/crc/models/workflow.py
index 9029ac6b..718dfccf 100644
--- a/crc/models/workflow.py
+++ b/crc/models/workflow.py
@@ -5,6 +5,7 @@ from marshmallow import EXCLUDE
 from marshmallow_sqlalchemy import SQLAlchemyAutoSchema
 
 from crc import db
+from crc.models.file import FileModel, FileDataModel
 
 
 class WorkflowSpecCategoryModel(db.Model):
@@ -67,6 +68,14 @@ class WorkflowStatus(enum.Enum):
     complete = "complete"
 
 
+class WorkflowSpecDependencyFile(db.Model):
+    """Connects a workflow to the version of the specification files it depends on to execute"""
+    file_data_id = db.Column(db.Integer, db.ForeignKey(FileDataModel.id), primary_key=True)
+    workflow_id = db.Column(db.Integer, db.ForeignKey("workflow.id"), primary_key=True)
+
+    file_data = db.relationship(FileDataModel)
+
+
 class WorkflowModel(db.Model):
     __tablename__ = 'workflow'
     id = db.Column(db.Integer, primary_key=True)
@@ -76,7 +85,13 @@ class WorkflowModel(db.Model):
     study = db.relationship("StudyModel", backref='workflow')
     workflow_spec_id = db.Column(db.String, db.ForeignKey('workflow_spec.id'))
     workflow_spec = db.relationship("WorkflowSpecModel")
-    spec_version = db.Column(db.String)
     total_tasks = db.Column(db.Integer, default=0)
     completed_tasks = db.Column(db.Integer, default=0)
     last_updated = db.Column(db.DateTime)
+    # Order By is important or generating hashes on reviews.
+    dependencies = db.relationship(WorkflowSpecDependencyFile, cascade="all, delete, delete-orphan",
+                                   order_by="WorkflowSpecDependencyFile.file_data_id")
+
+    def spec_version(self):
+        dep_ids = list(dep.file_data_id for dep in self.dependencies)
+        return "-".join(str(dep_ids))
diff --git a/crc/scripts/complete_template.py b/crc/scripts/complete_template.py
index 2acc1c4a..59f63158 100644
--- a/crc/scripts/complete_template.py
+++ b/crc/scripts/complete_template.py
@@ -59,13 +59,13 @@ Takes two arguments:
 
         file_data_model = None
         if workflow is not None:
-            # Get the workflow's latest files
-            joined_file_data_models = WorkflowProcessor\
-                .get_file_models_for_version(workflow.workflow_spec_id, workflow.spec_version)
-
-            for joined_file_data in joined_file_data_models:
-                if joined_file_data.file_model.name == file_name:
-                    file_data_model = session.query(FileDataModel).filter_by(id=joined_file_data.id).first()
+            # Get the workflow specification file with the given name.
+            file_data_models = FileService.get_spec_data_files(
+                workflow_spec_id=workflow.workflow_spec_id,
+                workflow_id=workflow.id)
+            for file_data in file_data_models:
+                if file_data.file_model.name == file_name:
+                    file_data_model = file_data
 
         if workflow is None or file_data_model is None:
             file_data_model = FileService.get_workflow_file_data(task.workflow, file_name)
diff --git a/crc/services/approval_service.py b/crc/services/approval_service.py
index f247ed09..8a13e6c2 100644
--- a/crc/services/approval_service.py
+++ b/crc/services/approval_service.py
@@ -3,8 +3,10 @@ from datetime import datetime
 from sqlalchemy import desc
 
 from crc import db, session
+from crc.api.common import ApiError
 
 from crc.models.approval import ApprovalModel, ApprovalStatus, ApprovalFile
+from crc.models.workflow import WorkflowModel
 from crc.services.file_service import FileService
 
 
@@ -51,15 +53,22 @@ class ApprovalService(object):
 
         # Construct as hash of the latest files to see if things have changed since
         # the last approval.
-        latest_files = FileService.get_workflow_files(workflow_id)
-        current_workflow_hash = ApprovalService._generate_workflow_hash(latest_files)
+        workflow = db.session.query(WorkflowModel).filter(WorkflowModel.id == workflow_id).first()
+        workflow_data_files = FileService.get_workflow_data_files(workflow_id)
+        current_data_file_ids = list(data_file.id for data_file in workflow_data_files)
+
+        if len(current_data_file_ids) == 0:
+            raise ApiError("invalid_workflow_approval", "You can't create an approval for a workflow that has"
+                                                        "no files to approve in it.")
 
         # If an existing approval request exists and no changes were made, do nothing.
         # If there is an existing approval request for a previous version of the workflow
         # then add a new request, and cancel any waiting/pending requests.
         if latest_approval_request:
-            # We could just compare the ApprovalFile lists here and do away with this hash.
-            if latest_approval_request.workflow_hash == current_workflow_hash:
+            request_file_ids = list(file.file_data_id for file in latest_approval_request.approval_files)
+            current_data_file_ids.sort()
+            request_file_ids.sort()
+            if current_data_file_ids == request_file_ids:
                 return  # This approval already exists.
             else:
                 latest_approval_request.status = ApprovalStatus.CANCELED.value
@@ -71,27 +80,18 @@ class ApprovalService(object):
         model = ApprovalModel(study_id=study_id, workflow_id=workflow_id,
                               approver_uid=approver_uid, status=ApprovalStatus.WAITING.value,
                               message="", date_created=datetime.now(),
-                              version=version, workflow_hash=current_workflow_hash)
-        approval_files = ApprovalService._create_approval_files(latest_files, model)
+                              version=version)
+        approval_files = ApprovalService._create_approval_files(workflow_data_files, model)
         db.session.add(model)
         db.session.add_all(approval_files)
         db.session.commit()
 
     @staticmethod
-    def _create_approval_files(files, approval):
+    def _create_approval_files(workflow_data_files, approval):
         """Currently based exclusively on the status of files associated with a workflow."""
         file_approval_models = []
-        for file in files:
-            file_approval_models.append(ApprovalFile(file_id=file.id,
-                                                     approval=approval,
-                                                     file_version=file.latest_version))
+        for file_data in workflow_data_files:
+            file_approval_models.append(ApprovalFile(file_data_id=file_data.id,
+                                                     approval=approval))
         return file_approval_models
 
-    @staticmethod
-    def _generate_workflow_hash(files):
-        """Currently based exclusively on the status of files associated with a workflow."""
-        version_array = []
-        for file in files:
-            version_array.append(str(file.id) + "[" + str(file.latest_version) + "]")
-        full_version = "-".join(version_array)
-        return full_version
diff --git a/crc/services/file_service.py b/crc/services/file_service.py
index 493f33ec..13466a0e 100644
--- a/crc/services/file_service.py
+++ b/crc/services/file_service.py
@@ -5,13 +5,14 @@ from datetime import datetime
 from uuid import UUID
 from xml.etree import ElementTree
 
+from SpiffWorkflow.bpmn.parser.ValidationException import ValidationException
 from pandas import ExcelFile
+from sqlalchemy import desc
 
 from crc import session
 from crc.api.common import ApiError
 from crc.models.file import FileType, FileDataModel, FileModel, LookupFileModel, LookupDataModel
-from crc.models.workflow import WorkflowSpecModel, WorkflowModel
-from crc.services.workflow_processor import WorkflowProcessor
+from crc.models.workflow import WorkflowSpecModel, WorkflowModel, WorkflowSpecDependencyFile
 
 
 class FileService(object):
@@ -111,12 +112,12 @@ class FileService(object):
     def update_file(file_model, binary_data, content_type):
         session.flush()  # Assure the database is up-to-date before running this.
 
-        file_data_model = session.query(FileDataModel). \
-            filter_by(file_model_id=file_model.id,
-                      version=file_model.latest_version
-                      ).with_for_update().first()
+        latest_data_model = session.query(FileDataModel). \
+            filter(FileDataModel.file_model_id == file_model.id).\
+            order_by(desc(FileDataModel.date_created)).first()
+
         md5_checksum = UUID(hashlib.md5(binary_data).hexdigest())
-        if (file_data_model is not None) and (md5_checksum == file_data_model.md5_hash):
+        if (latest_data_model is not None) and (md5_checksum == latest_data_model.md5_hash):
             # This file does not need to be updated, it's the same file.
             return file_model
 
@@ -130,28 +131,50 @@ class FileService(object):
             file_model.type = FileType[file_extension]
             file_model.content_type = content_type
 
-        if file_data_model is None:
+        if latest_data_model is None:
             version = 1
         else:
-            version = file_data_model.version + 1
+            version = latest_data_model.version + 1
 
         # If this is a BPMN, extract the process id.
         if file_model.type == FileType.bpmn:
             bpmn: ElementTree.Element = ElementTree.fromstring(binary_data)
-            file_model.primary_process_id = WorkflowProcessor.get_process_id(bpmn)
+            file_model.primary_process_id = FileService.get_process_id(bpmn)
 
-        file_model.latest_version = version
         new_file_data_model = FileDataModel(
             data=binary_data, file_model_id=file_model.id, file_model=file_model,
-            version=version, md5_hash=md5_checksum, last_updated=datetime.now()
+            version=version, md5_hash=md5_checksum, date_created=datetime.now()
         )
-
         session.add_all([file_model, new_file_data_model])
         session.commit()
         session.flush()  # Assure the id is set on the model before returning it.
 
         return file_model
 
+    @staticmethod
+    def get_process_id(et_root: ElementTree.Element):
+        process_elements = []
+        for child in et_root:
+            if child.tag.endswith('process') and child.attrib.get('isExecutable', False):
+                process_elements.append(child)
+
+        if len(process_elements) == 0:
+            raise ValidationException('No executable process tag found')
+
+        # There are multiple root elements
+        if len(process_elements) > 1:
+
+            # Look for the element that has the startEvent in it
+            for e in process_elements:
+                this_element: ElementTree.Element = e
+                for child_element in list(this_element):
+                    if child_element.tag.endswith('startEvent'):
+                        return this_element.attrib['id']
+
+            raise ValidationException('No start event found in %s' % et_root.attrib['id'])
+
+        return process_elements[0].attrib['id']
+
     @staticmethod
     def get_files_for_study(study_id, irb_doc_code=None):
         query = session.query(FileModel).\
@@ -176,23 +199,51 @@ class FileService(object):
 
         if name:
             query = query.filter_by(name=name)
+        query = query.order_by(FileModel.id)
 
         results = query.all()
         return results
 
     @staticmethod
-    def get_file_data(file_id, file_model=None, version=None):
+    def get_spec_data_files(workflow_spec_id, workflow_id=None):
+        """Returns all the FileDataModels related to a workflow specification.
+        If a workflow is specified, returns the version of the spec relatted
+        to that workflow, otherwise, returns the lastes files."""
+        if workflow_id:
+            files = session.query(FileDataModel) \
+                .join(WorkflowSpecDependencyFile) \
+                .filter(WorkflowSpecDependencyFile.workflow_id == workflow_id) \
+                .order_by(FileDataModel.id).all()
+            return files
+        else:
+            """Returns all the latest files related to a workflow specification"""
+            file_models = FileService.get_files(workflow_spec_id=workflow_spec_id)
+            latest_data_files = []
+            for file_model in file_models:
+                latest_data_files.append(FileService.get_file_data(file_model.id))
+            return latest_data_files
 
-        """Returns the file_data that is associated with the file model id, if an actual file_model
-        is provided, uses that rather than looking it up again."""
-        if file_model is None:
-            file_model = session.query(FileModel).filter(FileModel.id == file_id).first()
-        if version is None:
-            version = file_model.latest_version
-        return session.query(FileDataModel) \
-            .filter(FileDataModel.file_model_id == file_id) \
-            .filter(FileDataModel.version == version) \
-            .first()
+    @staticmethod
+    def get_workflow_data_files(workflow_id=None):
+        """Returns all the FileDataModels related to a running workflow -
+        So these are the latest data files that were uploaded or generated
+        that go along with this workflow.  Not related to the spec in any way"""
+        file_models = FileService.get_files(workflow_id=workflow_id)
+        latest_data_files = []
+        for file_model in file_models:
+            latest_data_files.append(FileService.get_file_data(file_model.id))
+        return latest_data_files
+
+    @staticmethod
+    def get_file_data(file_id: int, version: int = None):
+        """Returns the file data with the given version, or the lastest file, if version isn't provided."""
+        query = session.query(FileDataModel) \
+            .filter(FileDataModel.file_model_id == file_id)
+        if version:
+            query = query.filter(FileDataModel.version == version)
+        else:
+            query = query.order_by(desc(FileDataModel.date_created))
+        return query.first()
 
     @staticmethod
     def get_reference_file_data(file_name):
@@ -201,7 +252,7 @@ class FileService(object):
             filter(FileModel.name == file_name).first()
         if not file_model:
             raise ApiError("file_not_found", "There is no reference file with the name '%s'" % file_name)
-        return FileService.get_file_data(file_model.id, file_model)
+        return FileService.get_file_data(file_model.id)
 
     @staticmethod
     def get_workflow_file_data(workflow, file_name):
diff --git a/crc/services/study_service.py b/crc/services/study_service.py
index 68f760e1..98a8d15a 100644
--- a/crc/services/study_service.py
+++ b/crc/services/study_service.py
@@ -78,6 +78,8 @@ class StudyService(object):
     def delete_workflow(workflow):
         for file in session.query(FileModel).filter_by(workflow_id=workflow.id).all():
             FileService.delete_file(file.id)
+        for deb in workflow.dependencies:
+            session.delete(deb)
         session.query(TaskEventModel).filter_by(workflow_id=workflow.id).delete()
         session.query(WorkflowModel).filter_by(id=workflow.id).delete()
 
diff --git a/crc/services/workflow_processor.py b/crc/services/workflow_processor.py
index d4e7c08e..0834cac1 100644
--- a/crc/services/workflow_processor.py
+++ b/crc/services/workflow_processor.py
@@ -1,8 +1,7 @@
-import random
 import re
-import string
 import xml.etree.ElementTree as ElementTree
 from datetime import datetime
+from typing import List
 
 from SpiffWorkflow import Task as SpiffTask, WorkflowException
 from SpiffWorkflow.bpmn.BpmnScriptEngine import BpmnScriptEngine
@@ -13,14 +12,15 @@ from SpiffWorkflow.bpmn.workflow import BpmnWorkflow
 from SpiffWorkflow.camunda.parser.CamundaParser import CamundaParser
 from SpiffWorkflow.dmn.parser.BpmnDmnParser import BpmnDmnParser
 from SpiffWorkflow.exceptions import WorkflowTaskExecException
-from SpiffWorkflow.operators import Operator
 from SpiffWorkflow.specs import WorkflowSpec
+from sqlalchemy import desc
 
 from crc import session
 from crc.api.common import ApiError
 from crc.models.file import FileDataModel, FileModel, FileType
-from crc.models.workflow import WorkflowStatus, WorkflowModel
+from crc.models.workflow import WorkflowStatus, WorkflowModel, WorkflowSpecDependencyFile
 from crc.scripts.script import Script
+from crc.services.file_service import FileService
 
 
 class CustomBpmnScriptEngine(BpmnScriptEngine):
@@ -48,7 +48,7 @@ class CustomBpmnScriptEngine(BpmnScriptEngine):
             mod = __import__(module_name, fromlist=[class_name])
             klass = getattr(mod, class_name)
             study_id = task.workflow.data[WorkflowProcessor.STUDY_ID_KEY]
-            if(WorkflowProcessor.WORKFLOW_ID_KEY in task.workflow.data):
+            if WorkflowProcessor.WORKFLOW_ID_KEY in task.workflow.data:
                 workflow_id = task.workflow.data[WorkflowProcessor.WORKFLOW_ID_KEY]
             else:
                 workflow_id = None
@@ -75,7 +75,7 @@ class CustomBpmnScriptEngine(BpmnScriptEngine):
         Evaluate the given expression, within the context of the given task and
         return the result.
         """
-        exp,valid = self.validateExpression(expression)
+        exp, valid = self.validateExpression(expression)
         return self._eval(exp, **task.data)
 
     @staticmethod
@@ -108,18 +108,22 @@ class WorkflowProcessor(object):
         If neither flag is set, it will use the same version of the specification that was used to originally
         create the workflow model. """
         self.workflow_model = workflow_model
-        orig_version = workflow_model.spec_version
-        if soft_reset or workflow_model.spec_version is None:
-            self.workflow_model.spec_version = WorkflowProcessor.get_latest_version_string(
-                workflow_model.workflow_spec_id)
 
-        spec = self.get_spec(workflow_model.workflow_spec_id, workflow_model.spec_version)
+        if soft_reset or len(workflow_model.dependencies) == 0:
+            self.spec_data_files = FileService.get_spec_data_files(
+                workflow_spec_id=workflow_model.workflow_spec_id)
+        else:
+            self.spec_data_files = FileService.get_spec_data_files(
+                workflow_spec_id=workflow_model.workflow_spec_id,
+                workflow_id=workflow_model.id)
+
+        spec = self.get_spec(self.spec_data_files, workflow_model.workflow_spec_id)
         self.workflow_spec_id = workflow_model.workflow_spec_id
         try:
             self.bpmn_workflow = self.__get_bpmn_workflow(workflow_model, spec)
             self.bpmn_workflow.script_engine = self._script_engine
 
-            if not self.WORKFLOW_ID_KEY in self.bpmn_workflow.data:
+            if self.WORKFLOW_ID_KEY not in self.bpmn_workflow.data:
                 if not workflow_model.id:
                     session.add(workflow_model)
                     session.commit()
@@ -132,22 +136,26 @@ class WorkflowProcessor(object):
                 self.save()
 
         except KeyError as ke:
-            if soft_reset:
-                # Undo the soft-reset.
-                workflow_model.spec_version = orig_version
             raise ApiError(code="unexpected_workflow_structure",
                            message="Failed to deserialize workflow"
                                    " '%s' version %s, due to a mis-placed or missing task '%s'" %
-                                   (self.workflow_spec_id, workflow_model.spec_version, str(ke)) +
-                           " This is very likely due to a soft reset where there was a structural change.")
+                                   (self.workflow_spec_id, self.get_version_string(), str(ke)) +
+                                   " This is very likely due to a soft reset where there was a structural change.")
         if hard_reset:
             # Now that the spec is loaded, get the data and rebuild the bpmn with the new details
-            workflow_model.spec_version = self.hard_reset()
+            self.hard_reset()
             workflow_model.bpmn_workflow_json = WorkflowProcessor._serializer.serialize_workflow(self.bpmn_workflow)
             self.save()
+        if soft_reset:
+            self.save()
+
+        # set whether this is the latest spec file.
+        if self.spec_data_files == FileService.get_spec_data_files(workflow_spec_id=workflow_model.workflow_spec_id):
+            self.is_latest_spec = True
+        else:
+            self.is_latest_spec = False
 
     def __get_bpmn_workflow(self, workflow_model: WorkflowModel, spec: WorkflowSpec):
-
         if workflow_model.bpmn_workflow_json:
             bpmn_workflow = self._serializer.deserialize_workflow(workflow_model.bpmn_workflow_json, workflow_spec=spec)
         else:
@@ -159,44 +167,32 @@ class WorkflowProcessor(object):
 
     def save(self):
         """Saves the current state of this processor to the database """
-        workflow_model = self.workflow_model
-        workflow_model.bpmn_workflow_json = self.serialize()
+        self.workflow_model.bpmn_workflow_json = self.serialize()
         complete_states = [SpiffTask.CANCELLED, SpiffTask.COMPLETED]
         tasks = list(self.get_all_user_tasks())
-        workflow_model.status = self.get_status()
-        workflow_model.total_tasks = len(tasks)
-        workflow_model.completed_tasks = sum(1 for t in tasks if t.state in complete_states)
-        workflow_model.last_updated = datetime.now()
-        session.add(workflow_model)
+        self.workflow_model.status = self.get_status()
+        self.workflow_model.total_tasks = len(tasks)
+        self.workflow_model.completed_tasks = sum(1 for t in tasks if t.state in complete_states)
+        self.workflow_model.last_updated = datetime.now()
+        self.update_dependencies(self.spec_data_files)
+        session.add(self.workflow_model)
         session.commit()
 
-    @staticmethod
-    def run_master_spec(spec_model, study):
-        """Executes a BPMN specification for the given study, without recording any information to the database
-        Useful for running the master specification, which should not persist. """
-        version = WorkflowProcessor.get_latest_version_string(spec_model.id)
-        spec = WorkflowProcessor.get_spec(spec_model.id, version)
-        try:
-            bpmn_workflow = BpmnWorkflow(spec, script_engine=WorkflowProcessor._script_engine)
-            bpmn_workflow.data[WorkflowProcessor.STUDY_ID_KEY] = study.id
-            bpmn_workflow.data[WorkflowProcessor.VALIDATION_PROCESS_KEY] = False
-            bpmn_workflow.do_engine_steps()
-        except WorkflowException as we:
-            raise ApiError.from_task_spec("error_running_master_spec",  str(we), we.sender)
-
-        if not bpmn_workflow.is_completed():
-            raise ApiError("master_spec_not_automatic",
-                           "The master spec should only contain fully automated tasks, it failed to complete.")
-
-        return bpmn_workflow.last_task.data
+    def get_version_string(self):
+        # this could potentially become expensive to load all the data in the data models.
+        # in which case we might consider using a deferred loader for the actual data, but
+        # trying not to pre-optimize.
+        file_data_models = FileService.get_spec_data_files(self.workflow_model.workflow_spec_id,
+                                                           self.workflow_model.id)
+        return WorkflowProcessor.__get_version_string_for_data_models(file_data_models)
 
     @staticmethod
-    def get_parser():
-        parser = MyCustomParser()
-        return parser
+    def get_latest_version_string_for_spec(spec_id):
+        file_data_models = FileService.get_spec_data_files(spec_id)
+        return WorkflowProcessor.__get_version_string_for_data_models(file_data_models)
 
     @staticmethod
-    def get_latest_version_string(workflow_spec_id):
+    def __get_version_string_for_data_models(file_data_models):
         """Version is in the format v[VERSION] (FILE_ID_LIST)
          For example, a single bpmn file with only one version would be
          v1 (12)  Where 12 is the id of the file data model that is used to create the
@@ -205,10 +201,6 @@ class WorkflowProcessor(object):
          a Spec that includes a BPMN, DMN, an a Word file all on the first
          version would be v1.1.1 (12.45.21)"""
 
-        # this could potentially become expensive to load all the data in the data models.
-        # in which case we might consider using a deferred loader for the actual data, but
-        # trying not to pre-optimize.
-        file_data_models = WorkflowProcessor.__get_latest_file_models(workflow_spec_id)
         major_version = 0  # The version of the primary file.
         minor_version = []  # The versions of the minor files if any.
         file_ids = []
@@ -224,60 +216,72 @@ class WorkflowProcessor(object):
         full_version = "v%s (%s)" % (version, files)
         return full_version
 
-    @staticmethod
-    def get_file_models_for_version(workflow_spec_id, version):
-        file_id_strings = re.findall('\((.*)\)', version)[0].split(".")
-        file_ids = [int(i) for i in file_id_strings]
-        files = session.query(FileDataModel)\
-            .join(FileModel) \
-            .filter(FileModel.workflow_spec_id == workflow_spec_id)\
-            .filter(FileDataModel.id.in_(file_ids)).all()
-        if len(files) != len(file_ids):
-            raise ApiError("invalid_version",
-                           "The version '%s' of workflow specification '%s' is invalid. " %
-                           (version, workflow_spec_id) +
-                           " Unable to locate the correct files to recreate it.")
-        return files
+
+
+    def update_dependencies(self, spec_data_files):
+        existing_dependencies = FileService.get_spec_data_files(
+            workflow_spec_id=self.workflow_model.workflow_spec_id,
+            workflow_id=self.workflow_model.id)
+
+        # Don't save the dependencies if they haven't changed.
+        if existing_dependencies == spec_data_files:
+            return
+
+        # Remove all existing dependencies, and replace them.
+        self.workflow_model.dependencies = []
+        for file_data in spec_data_files:
+            self.workflow_model.dependencies.append(WorkflowSpecDependencyFile(file_data_id=file_data.id))
 
     @staticmethod
-    def __get_latest_file_models(workflow_spec_id):
-        """Returns all the latest files related to a workflow specification"""
-        return session.query(FileDataModel) \
-            .join(FileModel) \
-            .filter(FileModel.workflow_spec_id == workflow_spec_id)\
-            .filter(FileDataModel.version == FileModel.latest_version)\
-            .order_by(FileModel.id)\
-            .all()
+    def run_master_spec(spec_model, study):
+        """Executes a BPMN specification for the given study, without recording any information to the database
+        Useful for running the master specification, which should not persist. """
+        spec_data_files = FileService.get_spec_data_files(spec_model.id)
+        spec = WorkflowProcessor.get_spec(spec_data_files, spec_model.id)
+        try:
+            bpmn_workflow = BpmnWorkflow(spec, script_engine=WorkflowProcessor._script_engine)
+            bpmn_workflow.data[WorkflowProcessor.STUDY_ID_KEY] = study.id
+            bpmn_workflow.data[WorkflowProcessor.VALIDATION_PROCESS_KEY] = False
+            bpmn_workflow.do_engine_steps()
+        except WorkflowException as we:
+            raise ApiError.from_task_spec("error_running_master_spec", str(we), we.sender)
+
+        if not bpmn_workflow.is_completed():
+            raise ApiError("master_spec_not_automatic",
+                           "The master spec should only contain fully automated tasks, it failed to complete.")
+
+        return bpmn_workflow.last_task.data
 
     @staticmethod
-    def get_spec(workflow_spec_id, version=None):
-        """Returns the requested version of the specification,
-        or the latest version if none is specified."""
+    def get_parser():
+        parser = MyCustomParser()
+        return parser
+
+    @staticmethod
+    def get_spec(file_data_models: List[FileDataModel], workflow_spec_id):
+        """Returns a SpiffWorkflow specification for the given workflow spec,
+        using the files provided.  The Workflow_spec_id is only used to generate
+        better error messages."""
         parser = WorkflowProcessor.get_parser()
         process_id = None
 
-        if version is None:
-            file_data_models = WorkflowProcessor.__get_latest_file_models(workflow_spec_id)
-        else:
-            file_data_models = WorkflowProcessor.get_file_models_for_version(workflow_spec_id, version)
-
         for file_data in file_data_models:
             if file_data.file_model.type == FileType.bpmn:
                 bpmn: ElementTree.Element = ElementTree.fromstring(file_data.data)
                 if file_data.file_model.primary:
-                    process_id = WorkflowProcessor.get_process_id(bpmn)
+                    process_id = FileService.get_process_id(bpmn)
                 parser.add_bpmn_xml(bpmn, filename=file_data.file_model.name)
             elif file_data.file_model.type == FileType.dmn:
                 dmn: ElementTree.Element = ElementTree.fromstring(file_data.data)
                 parser.add_dmn_xml(dmn, filename=file_data.file_model.name)
         if process_id is None:
-            raise(ApiError(code="no_primary_bpmn_error",
-                           message="There is no primary BPMN model defined for workflow %s" % workflow_spec_id))
+            raise (ApiError(code="no_primary_bpmn_error",
+                            message="There is no primary BPMN model defined for workflow %s" % workflow_spec_id))
         try:
             spec = parser.get_spec(process_id)
         except ValidationException as ve:
             raise ApiError(code="workflow_validation_error",
-                           message="Failed to parse Workflow Specification '%s' %s." % (workflow_spec_id, version) +
+                           message="Failed to parse Workflow Specification '%s'" % workflow_spec_id +
                                    "Error is %s" % str(ve),
                            file_name=ve.filename,
                            task_id=ve.id,
@@ -301,8 +305,8 @@ class WorkflowProcessor(object):
 
          Returns the new version.
          """
-        version = WorkflowProcessor.get_latest_version_string(self.workflow_spec_id)
-        spec = WorkflowProcessor.get_spec(self.workflow_spec_id)  # Force latest version by NOT specifying version
+        self.spec_data_files = FileService.get_spec_data_files(workflow_spec_id=self.workflow_spec_id)
+        spec = WorkflowProcessor.get_spec(self.spec_data_files, self.workflow_spec_id)
         # spec = WorkflowProcessor.get_spec(self.workflow_spec_id, version)
         bpmn_workflow = BpmnWorkflow(spec, script_engine=self._script_engine)
         bpmn_workflow.data = self.bpmn_workflow.data
@@ -310,14 +314,10 @@ class WorkflowProcessor(object):
             task.data = self.bpmn_workflow.last_task.data
         bpmn_workflow.do_engine_steps()
         self.bpmn_workflow = bpmn_workflow
-        return version
 
     def get_status(self):
         return self.status_of(self.bpmn_workflow)
 
-    def get_spec_version(self):
-        return self.workflow_model.spec_version
-
     def do_engine_steps(self):
         try:
             self.bpmn_workflow.do_engine_steps()
@@ -398,32 +398,7 @@ class WorkflowProcessor(object):
         return [t for t in all_tasks
                 if not self.bpmn_workflow._is_engine_task(t.task_spec) and t.state in [t.COMPLETED, t.CANCELLED]]
 
-    @staticmethod
-    def get_process_id(et_root: ElementTree.Element):
-        process_elements = []
-        for child in et_root:
-            if child.tag.endswith('process') and child.attrib.get('isExecutable', False):
-                process_elements.append(child)
-
-        if len(process_elements) == 0:
-            raise ValidationException('No executable process tag found')
-
-        # There are multiple root elements
-        if len(process_elements) > 1:
-
-            # Look for the element that has the startEvent in it
-            for e in process_elements:
-                this_element: ElementTree.Element = e
-                for child_element in list(this_element):
-                    if child_element.tag.endswith('startEvent'):
-                        return this_element.attrib['id']
-
-            raise ValidationException('No start event found in %s' % et_root.attrib['id'])
-
-        return process_elements[0].attrib['id']
-
     def get_nav_item(self, task):
         for nav_item in self.bpmn_workflow.get_nav_list():
             if nav_item['task_id'] == task.id:
                 return nav_item
-
diff --git a/crc/services/workflow_service.py b/crc/services/workflow_service.py
index 1f6cfe8f..eb488537 100644
--- a/crc/services/workflow_service.py
+++ b/crc/services/workflow_service.py
@@ -40,8 +40,10 @@ class WorkflowService(object):
     def test_spec(cls, spec_id):
         """Runs a spec through it's paces to see if it results in any errors.  Not fool-proof, but a good
         sanity check."""
-        version = WorkflowProcessor.get_latest_version_string(spec_id)
-        spec = WorkflowProcessor.get_spec(spec_id, version)
+
+        spec = WorkflowProcessor.get_spec(
+            file_data_models=FileService.get_spec_data_files(workflow_spec_id=spec_id),
+            workflow_spec_id=spec_id)
         bpmn_workflow = BpmnWorkflow(spec, script_engine=CustomBpmnScriptEngine())
         bpmn_workflow.data[WorkflowProcessor.STUDY_ID_KEY] = 1
         bpmn_workflow.data[WorkflowProcessor.WORKFLOW_ID_KEY] = spec_id
@@ -269,7 +271,7 @@ class WorkflowService(object):
             user_uid=g.user.uid,
             workflow_id=workflow_model.id,
             workflow_spec_id=workflow_model.workflow_spec_id,
-            spec_version=workflow_model.spec_version,
+            spec_version=processor.get_version_string(),
             action=action,
             task_id=task.id,
             task_name=task.name,
diff --git a/tests/test_approvals_service.py b/tests/test_approvals_service.py
index 0ae37941..1ec6db75 100644
--- a/tests/test_approvals_service.py
+++ b/tests/test_approvals_service.py
@@ -9,7 +9,12 @@ from crc.services.workflow_processor import WorkflowProcessor
 class TestApprovalsService(BaseTest):
 
     def test_create_approval_record(self):
+        self.create_reference_document()
         workflow = self.create_workflow("empty_workflow")
+        FileService.add_workflow_file(workflow_id=workflow.id,
+                                      name="anything.png", content_type="text",
+                                      binary_data=b'5678', irb_doc_code="UVACompl_PRCAppr" )
+
         ApprovalService.add_approval(study_id=workflow.study_id, workflow_id=workflow.id, approver_uid="dhf8r")
         self.assertEquals(1, db.session.query(ApprovalModel).count())
         model = db.session.query(ApprovalModel).first()
@@ -17,10 +22,14 @@ class TestApprovalsService(BaseTest):
         self.assertEquals(workflow.id, model.workflow_id)
         self.assertEquals("dhf8r", model.approver_uid)
         self.assertEquals(1, model.version)
-        self.assertIsNotNone(model.workflow_hash)
 
     def test_new_requests_dont_add_if_approval_exists_for_current_workflow(self):
+        self.create_reference_document()
         workflow = self.create_workflow("empty_workflow")
+        FileService.add_workflow_file(workflow_id=workflow.id,
+                                      name="anything.png", content_type="text",
+                                      binary_data=b'5678', irb_doc_code="UVACompl_PRCAppr" )
+
         ApprovalService.add_approval(study_id=workflow.study_id, workflow_id=workflow.id, approver_uid="dhf8r")
         ApprovalService.add_approval(study_id=workflow.study_id, workflow_id=workflow.id, approver_uid="dhf8r")
         self.assertEquals(1, db.session.query(ApprovalModel).count())
@@ -31,15 +40,15 @@ class TestApprovalsService(BaseTest):
         self.load_example_data()
         self.create_reference_document()
         workflow = self.create_workflow('empty_workflow')
-        processor = WorkflowProcessor(workflow)
-        task = processor.next_task()
+        FileService.add_workflow_file(workflow_id=workflow.id,
+                                      name="anything.png", content_type="text",
+                                      binary_data=b'5678', irb_doc_code="AD_CoCAppr")
 
         ApprovalService.add_approval(study_id=workflow.study_id, workflow_id=workflow.id, approver_uid="dhf8r")
 
-        irb_code_1 = "UVACompl_PRCAppr"  # The first file referenced in pb required docs.
         FileService.add_workflow_file(workflow_id=workflow.id,
                                       name="anything.png", content_type="text",
-                                      binary_data=b'5678', irb_doc_code=irb_code_1)
+                                      binary_data=b'5678', irb_doc_code="UVACompl_PRCAppr")
 
         ApprovalService.add_approval(study_id=workflow.study_id, workflow_id=workflow.id, approver_uid="dhf8r")
         self.assertEquals(2, db.session.query(ApprovalModel).count())
@@ -48,38 +57,3 @@ class TestApprovalsService(BaseTest):
         self.assertEquals(2, models[1].version)
 
 
-    def test_generate_workflow_hash_and_version(self):
-        self.load_example_data()
-        self.create_reference_document()
-        workflow = self.create_workflow('empty_workflow')
-        processor = WorkflowProcessor(workflow)
-        task = processor.next_task()
-        irb_code_1 = "UVACompl_PRCAppr"  # The first file referenced in pb required docs.
-        irb_code_2 = "NonUVAIRB_AssuranceForm"  # The second file in above.
-        # Add a task file to the workflow.
-        FileService.add_workflow_file(workflow_id=workflow.id,
-                                      name="anything.png", content_type="text",
-                                      binary_data=b'5678', irb_doc_code=irb_code_1)
-        # Add a two form field files with the same irb_code, but different names
-        FileService.add_workflow_file(workflow_id=workflow.id,
-                                      name="anything.png", content_type="text",
-                                      binary_data=b'1234', irb_doc_code=irb_code_2)
-        FileService.add_workflow_file(workflow_id=workflow.id,
-                                      name="another_anything.png", content_type="text",
-                                      binary_data=b'5678', irb_doc_code=irb_code_2)
-
-
-        # Workflow hash should look be id[1]-id[1]-id[1]
-        # Sould be three files, each with a version of 1.
-        # where id is the file id, which we don't know, thus the regex.
-        latest_files = FileService.get_workflow_files(workflow.id)
-        self.assertRegexpMatches(ApprovalService._generate_workflow_hash(latest_files), "\d+\[1\]-\d+\[1\]-\d+\[1\]")
-
-        # Replace last file
-        # should now be id[1]-id[1]-id[2]
-        FileService.add_workflow_file(workflow_id=workflow.id,
-                                      irb_doc_code=irb_code_2,
-                                      name="another_anything.png", content_type="text",
-                                      binary_data=b'9999')
-        self.assertRegexpMatches(ApprovalService._generate_workflow_hash(latest_files), "\d+\[1\]-\d+\[1\]-\d+\[2\]")
-
diff --git a/tests/test_file_service.py b/tests/test_file_service.py
index 0b5ae5cf..705fef95 100644
--- a/tests/test_file_service.py
+++ b/tests/test_file_service.py
@@ -23,7 +23,11 @@ class TestFileService(BaseTest):
 
         file_models = FileService.get_workflow_files(workflow_id=workflow.id)
         self.assertEquals(1, len(file_models))
-        self.assertEquals(2, file_models[0].latest_version)
+
+        file_data = FileService.get_workflow_data_files(workflow_id=workflow.id)
+        self.assertEquals(1, len(file_data))
+        self.assertEquals(2, file_data[0].version)
+
 
     def test_add_file_from_form_increments_version_and_replaces_on_subsequent_add_with_same_name(self):
         self.load_example_data()
@@ -44,7 +48,10 @@ class TestFileService(BaseTest):
 
         file_models = FileService.get_workflow_files(workflow_id=workflow.id)
         self.assertEquals(1, len(file_models))
-        self.assertEquals(2, file_models[0].latest_version)
+
+        file_data = FileService.get_workflow_data_files(workflow_id=workflow.id)
+        self.assertEquals(1, len(file_data))
+        self.assertEquals(2, file_data[0].version)
 
     def test_add_file_from_form_allows_multiple_files_with_different_names(self):
         self.load_example_data()
@@ -64,5 +71,3 @@ class TestFileService(BaseTest):
                                       binary_data=b'5678')
         file_models = FileService.get_workflow_files(workflow_id=workflow.id)
         self.assertEquals(2, len(file_models))
-        self.assertEquals(1, file_models[0].latest_version)
-        self.assertEquals(1, file_models[1].latest_version)
\ No newline at end of file
diff --git a/tests/test_files_api.py b/tests/test_files_api.py
index 79f8dbf2..ecce309c 100644
--- a/tests/test_files_api.py
+++ b/tests/test_files_api.py
@@ -4,7 +4,7 @@ import json
 from tests.base_test import BaseTest
 
 from crc import session
-from crc.models.file import FileModel, FileType, FileModelSchema, FileDataModel
+from crc.models.file import FileModel, FileType, FileSchema, FileModelSchema
 from crc.models.workflow import WorkflowSpecModel
 from crc.services.file_service import FileService
 from crc.services.workflow_processor import WorkflowProcessor
@@ -165,16 +165,16 @@ class TestFilesApi(BaseTest):
                           content_type='multipart/form-data', headers=self.logged_in_headers())
         self.assert_success(rv)
         self.assertIsNotNone(rv.get_data())
-        json_data = json.loads(rv.get_data(as_text=True))
-        file = FileModelSchema().load(json_data, session=session)
-        self.assertEqual(2, file.latest_version)
-        self.assertEqual(FileType.bpmn, file.type)
-        self.assertEqual("application/octet-stream", file.content_type)
+        file_json = json.loads(rv.get_data(as_text=True))
+        self.assertEqual(2, file_json['latest_version'])
+        self.assertEqual(FileType.bpmn.value, file_json['type'])
+        self.assertEqual("application/octet-stream", file_json['content_type'])
         self.assertEqual(spec.id, file.workflow_spec_id)
 
         # Assure it is updated in the database and properly persisted.
         file_model = session.query(FileModel).filter(FileModel.id == file.id).first()
-        self.assertEqual(2, file_model.latest_version)
+        file_data = FileService.get_file_data(file_model.id)
+        self.assertEqual(2, file_data.version)
 
         rv = self.app.get('/v1.0/file/%i/data' % file.id, headers=self.logged_in_headers())
         self.assert_success(rv)
@@ -191,15 +191,13 @@ class TestFilesApi(BaseTest):
                            content_type='multipart/form-data', headers=self.logged_in_headers())
         self.assertIsNotNone(rv.get_data())
         json_data = json.loads(rv.get_data(as_text=True))
-        file = FileModelSchema().load(json_data, session=session)
-        self.assertEqual(1, file.latest_version)
+        self.assertEqual(1, json_data['latest_version'])
         data['file'] = io.BytesIO(self.minimal_bpmn("abcdef")), 'my_new_file.bpmn'
-        rv = self.app.put('/v1.0/file/%i/data' % file.id, data=data, follow_redirects=True,
+        rv = self.app.put('/v1.0/file/%i/data' % json_data['id'], data=data, follow_redirects=True,
                           content_type='multipart/form-data', headers=self.logged_in_headers())
         self.assertIsNotNone(rv.get_data())
         json_data = json.loads(rv.get_data(as_text=True))
-        file = FileModelSchema().load(json_data, session=session)
-        self.assertEqual(1, file.latest_version)
+        self.assertEqual(1, json_data['latest_version'])
 
     def test_get_file(self):
         self.load_example_data()
diff --git a/tests/test_request_approval_script.py b/tests/test_request_approval_script.py
index 142da5c5..2f4ab49e 100644
--- a/tests/test_request_approval_script.py
+++ b/tests/test_request_approval_script.py
@@ -1,3 +1,4 @@
+from crc.services.file_service import FileService
 from tests.base_test import BaseTest
 
 from crc.scripts.request_approval import RequestApproval
@@ -17,7 +18,10 @@ class TestRequestApprovalScript(BaseTest):
         processor = WorkflowProcessor(workflow)
         task = processor.next_task()
         task.data = {"study": {"approval1": "dhf8r", 'approval2':'lb3dp'}}
-
+        FileService.add_workflow_file(workflow_id=workflow.id,
+                                      irb_doc_code="UVACompl_PRCAppr",
+                                      name="anything.png", content_type="text",
+                                      binary_data=b'1234')
         script = RequestApproval()
         script.do_task(task, workflow.study_id, workflow.id, "study.approval1", "study.approval2")
         self.assertEquals(2, db.session.query(ApprovalModel).count())
diff --git a/tests/test_study_service.py b/tests/test_study_service.py
index aa77cc24..52babbb8 100644
--- a/tests/test_study_service.py
+++ b/tests/test_study_service.py
@@ -74,7 +74,6 @@ class TestStudyService(BaseTest):
 
         # workflow should not be started, and it should have 0 completed tasks, and 0 total tasks.
         self.assertEqual(WorkflowStatus.not_started, workflow.status)
-        self.assertEqual(None, workflow.spec_version)
         self.assertEqual(0, workflow.total_tasks)
         self.assertEqual(0, workflow.completed_tasks)
 
diff --git a/tests/test_tasks_api.py b/tests/test_tasks_api.py
index 176c2278..d95990b5 100644
--- a/tests/test_tasks_api.py
+++ b/tests/test_tasks_api.py
@@ -182,7 +182,6 @@ class TestTasksApi(BaseTest):
         self.assertEquals("Task 2b", nav[5]['title'])
         self.assertEquals("Task 3", nav[6]['title'])
 
-
     def test_document_added_to_workflow_shows_up_in_file_list(self):
         self.load_example_data()
         self.create_reference_document()
diff --git a/tests/test_workflow_processor.py b/tests/test_workflow_processor.py
index fe182e28..36d23755 100644
--- a/tests/test_workflow_processor.py
+++ b/tests/test_workflow_processor.py
@@ -254,12 +254,12 @@ class TestWorkflowProcessor(BaseTest):
         study = session.query(StudyModel).first()
         workflow_spec_model = self.load_test_spec("decision_table")
         processor = self.get_processor(study, workflow_spec_model)
-        self.assertTrue(processor.get_spec_version().startswith('v1.1'))
+        self.assertTrue(processor.get_version_string().startswith('v1.1'))
         file_service = FileService()
 
         file_service.add_workflow_spec_file(workflow_spec_model, "new_file.txt", "txt", b'blahblah')
         processor = self.get_processor(study, workflow_spec_model)
-        self.assertTrue(processor.get_spec_version().startswith('v1.1.1'))
+        self.assertTrue(processor.get_version_string().startswith('v1.1.1'))
 
         file_path = os.path.join(app.root_path, '..', 'tests', 'data', 'docx', 'docx.bpmn')
         file = open(file_path, "rb")
@@ -268,7 +268,7 @@ class TestWorkflowProcessor(BaseTest):
         file_model = db.session.query(FileModel).filter(FileModel.name == "decision_table.bpmn").first()
         file_service.update_file(file_model, data, "txt")
         processor = self.get_processor(study, workflow_spec_model)
-        self.assertTrue(processor.get_spec_version().startswith('v2.1.1'))
+        self.assertTrue(processor.get_version_string().startswith('v2.1.1'))
 
     def test_restart_workflow(self):
         self.load_example_data()
@@ -339,7 +339,7 @@ class TestWorkflowProcessor(BaseTest):
         # Assure that creating a new processor doesn't cause any issues, and maintains the spec version.
         processor.workflow_model.bpmn_workflow_json = processor.serialize()
         processor2 = WorkflowProcessor(processor.workflow_model)
-        self.assertTrue(processor2.get_spec_version().startswith("v1 ")) # Still at version 1.
+        self.assertFalse(processor2.is_latest_spec) # Still at version 1.
 
         # Do a hard reset, which should bring us back to the beginning, but retain the data.
         processor3 = WorkflowProcessor(processor.workflow_model, hard_reset=True)
@@ -349,10 +349,6 @@ class TestWorkflowProcessor(BaseTest):
         self.assertEqual("New Step", processor3.next_task().task_spec.description)
         self.assertEqual("blue", processor3.next_task().data["color"])
 
-    def test_get_latest_spec_version(self):
-        workflow_spec_model = self.load_test_spec("two_forms")
-        version = WorkflowProcessor.get_latest_version_string("two_forms")
-        self.assertTrue(version.startswith("v1 "))
 
     @patch('crc.services.protocol_builder.ProtocolBuilderService.get_studies')
     @patch('crc.services.protocol_builder.ProtocolBuilderService.get_investigators')