Roles of PDM and PLM software

Originally, engineering data was relatively simple: design files, parts lists and specifications. At the time, engineering data management software (EDMS) and later PDM allowed users to organize their product data, and apply rules for item identification and revision control. An associated electronic data library contained 2D CAD files and other design files.

However, with added complexity in product design, engineering data management has now evolved into two separate solutions:

There are good reasons — technical and operational — why these solutions have become distinct.

Technical differences between PDM & PLM

PDM: A file-based system for managing 3D models of physical objects

There may not be a one-to-one relationship between a CAD file and a part, and a CAD file generally can't represent non-mechanical information required for production.

In short, the computer folder/file system is the natural data environment for working with CAD files. Mechanical 3D CAD models require specialized file managers — a product data management (PDM) tool — to create, edit and move file relationships. Item re-use often requires copying the physical file from one model to another, or coordinating several models. Most CAD vendors provide their own PDM tool for these purposes.

PLM: A database system for managing products & processes

PLM systems have different classes of objects (primarily parts, documents and change forms) with distinct properties and behaviors. A bill of materials is a collection of database objects; document references and approved vendor sources are object lists.

Change forms can directly act on objects by, for instance, releasing a revised part and automatically ensuring all BOM components and supporting documents are released simultaneously. An object's Appears On (or "where used") displays its parent assemblies, referencing items and releasing/canceling change forms.

In a PLM system, a CAD file (or set of files) is simply one of many attributes that describe the part. Non-CAD files can also be attached, such as a Microsoft Word specification, vendor datasheet PDF, or even a customer email. Files can be attached to change forms and organization records. A PLM system can index the text contents of a file, and open a file with whatever Windows application recognizes its file type.

Operational differences between PDM & PLM

"There is no known way to handle the complex interrelationship between parts without access to a well designed Product Data Management system. A PLM system is even more useful!"

There can be overlap between PDM and PLM roles. In many companies, PLM and PDM tools are used side-by-side. A PDM system has deep knowledge about the CAD file model; a PLM system has broad knowledge about the product definition and relationships.

Specialized design environments (like CAD+PDM) feed the PLM system

Consider the various design disciplines that go into a new product:

• •Industrial, mechanical, electronic and software design
• •Documentation and graphics for installation and use
• •Requirements, specifications and procedures

All of these require some type of "design environment": mechanical CAD with model management; electronic circuit design and simulation; software development with source control; graphics tool; or simply a word processor. Each of these design environments produce design files that are coordinated with the other disciplines to ensure a coherent product.

The PLM system feeds design, test, procurement, production and service

Product information is divided between what's required specifically for engineering development, and what's needed to manage, purchase, manufacture and service the product.

The PLM system contains — and closely controls — the product data that users need from the development process. It ensures that:

PLM software for communication & control

PLM coordinates design intent and provides an orderly flow of approved data. PLM ensures that only the correct parts are ordered, produced and assembled according to valid & approved documentation. PLM is the central repository of the product definition: requirements; drawings; supplier datasheets; test results; assembly, test and inspection procedures; user documentation; and technical field support materials.

PLM systems prevent costly errors related to unapproved part substitutions, out-of-date documentation, incorrect part numbers, and even many clerical errors in transferring final designs into production. They can also answer questions about what had previously been used, who made changes and why, and what alternatives were considered and rejected.

PDXpert PLM software supports the complete product life cycle with: