PDM in plain English

Defining a need.

3D modeling software embeds external models into assemblies and drawings.  Doing so ensures that all parent documents (drawings and assemblies) are updated when the child document (part or assembly) is modified.  To do this, the parent documents contain links to the child documents.  These links are referred to as external references.  Retaining multiple revisions of 3D models, drawings, or other documents, external references can be cumbersome to manage.  Here are just a few issues:

1. How do you store multiple revisions of a single document?  If documents are stored with the same name in different directories, how can you ensure the correct revision of component is loaded with the parent document?  If documents are stored with different names, you have to reload the component, but that changes references in the parent document.
2. What revision of a component, belongs with a specific revision of a parent document?  There may be times when there is a need to access an older revision  of an assembly.  Without a data management software, how do you know you have the correct components loaded with the parent document?
3. A document was modified, but who changed it, and when?  You can look at the file properties to determine when the file was last saved, and who saved it, but this does not identify how many times the document was changed since it was created, and who did each of those changes.

With just these three scenarios, you can start to get an understanding of how complex a task it can be to manage multiple revisions of your documents by hand.

Product Data Management (PDM) in plain English

In its simplest terms, Product Data Management is securing and controlling the data used to create the products your company designs, engineers and manufactures.  This data includes, but is not limited to drawings, 3D models, schematics, decals and signage, etc…  Additional data such as FEA Analysis, manufacturing specifications, quotes, test results, etc… is also considered product data that needs to be managed and secured.

Product Data Management (PDM) software handles these tasks for you.  Even the simplest PDM packages offer these features:

• Document Vaulting - Stores each revision of your document in a safe location where it cannot become lost or accidentally modified.
• Document Check-in and Check-out – Document check-in is the capability to place a document into the vault.  This includes placing revised documents back into the vault.  Document check-out allows users to retrieve a vaulted document so it can be modified. Document check-out is limited to the latest revision documents only.  Once a document is checked out, no one else can check-out the document.  This prevents anyone from beginning a new change to a document that is already being changed. 
• File Relationship Management – Keeps track of what version of a component was used on each version of the parent document.
• Contains and Where Used – PDM software also records the parent/child relationships between revisions of child components and the revisions of parent documents.  This tracking provides a quick way to see what a document contains without opening the document.  This tracking also provides where-used capability that provides a list of parent documents that a component is used on. 
• Search – Any PDM software you look at needs to provide a quick and easy means for you to find the document you are looking for.  The more fields the software can search on, the mode refined your search can be.  Boolean (and, or, not) based searches improve the power of the search capabilities.
• Audit Trail – Keeps track of who checked the document in or out of the vault.  This tracking helps identify when a document was modified, and who modified it.  It can also keep track of who initiated the release process and who approved the document(s).

The vaulting, check-in, check-out, contains and where-used capabilities are minimum features for PDM packages.  Many of the PDM packages out on the market offer additional features, some of which are listed below.

• Workflow - A means to use software to track your current document release processes.  Example; After documents are modified, they can be placed in a pre-release state within the workflow.  Once documents are placed in this state, notifications are sent for appropriate people to review the documents.  From this state, the documents can be pushed further thru the release process, or rejected and pushed back for additional changes.  Using a workflow to track the status of documents in the release process provides a way to quickly determine where an ECN is within the process, and who or what may be holding up the process.
• Email notifications – Send emails to various individuals or groups to identify when they need to review or approve document changes.
• Vault replication – An automated means of copying the vaulted files and databases to multiple off-site locations.  This not only reduces file access times for those off-site locations, but it also provides a back-up of your vault.
• Batch processes – The server will do redundant or time consuming tasks such as print documents or PDF publishing.
• Web Portal – This allows people outside of the department or company (such as sales people or fabrication vendors) to have access to the latest documents as soon as they are released.

From this article, you should have at least gained an understanding of why you need to implement a Product Data Management package and a brief overview of some of the basic and advanced functionality available in many of the PDM software packages that are in the market.  In a future article, I will identify how to evaluate your needs and compare those needs against the features available in each of the PDM package offerings.