Essential elements of PLM
PLM can be thought of as both (a) a repository for all information that affects a product, and (b) a communication process between product stakeholders: principally marketing, engineering, manufacturing and field service. The PLM system is the first place where all product information from marketing and design comes together, and where it leaves in a form suitable for production and support.
A few analysts use "PLM" as an umbrella term that includes engineering CAD (for "information authoring"). But product-related authoring tools can include word processors; spreadsheet and graphics programs; and even requirements analysis and market assessment tools. PLM systems, on the other hand, are necessarily broad to encompass the entire reach of a product lifecycle, and therefore are primarily focused on data management, rather than data authoring.
The essential elements of PLM are:
Management of design and process documents
Product structure (bill of material) management
Central data vault (electronic file repository)
Part and document classification and metadata ("attribute") management
Materials content identification for environmental compliance
Product-focused project task assignment
Workflow and process management for approving changes
Multi-user secured access, including "electronic signature"
Data export for loading downstream ERP systems
Differences between PLM and PDM
PLM manages product information within a database
PLM specifies and controls the complete, approved engineering design: requirements, specifications, procedures, configurations. It defines the current product structures and planned changes, as well as maintains the history of all previous design decisions.
PLM data is usually created and managed by engineering in cooperation with other product managers in purchasing, production, quality, service and sales. It's the container for how to buy, fabricate, assemble, test, calibrate, inspect, install, repair and even sell the end product. PLM is a cross-department information storehouse, and its data is often exported to manufacturing systems and supply chain partners.
PLM manages objects – parts, documents, change forms, and supporting data – within a database. These objects have:
- Descriptive attributes like owning organization, identifying number, name/title, revision (technical content) and lifecycle (business rules for what can be done with that content), weight and unit of measure. CAD files (and any other files) can be attached to database records to further describe the object.
- Relationships to other objects: parts have requirements, specifications, inspection procedures, etc.; assemblies have components with quantities; purchased parts have approved sources; designed parts have design drawings.
These attributes and relationships are created, reviewed and approved using system rules and change workflows.
PDM manages CAD files within a computer file system
CAD drawings are files, and reside principally in a computer's file system or on a network share. A CAD file often represents a single part, but several files may represent one part or one file can represent multiple parts.
Product data management ("PDM") is a specialized file system manager, somewhat like a CAD-oriented Windows Explorer. PDM's primary job is to manage mechanical CAD files, and the linkages between related files. These related files (the "model") are usually in a proprietary format defined by the CAD vendor.
PDM assists in organizing the mechanical aspects of a product, but it's the CAD model (or its derivative drawings), and not PDM itself, that has utility to downstream users.