A Product Characteristic describes the part. A Process Characteristic describes the process control that makes that part feature happen. Each worksheet row, and each Reusable Library record, holds one or the other, never both.
Definitions
- Product Characteristic: a physical feature or property of an assembly or component part, usually described on the drawing, that can be measured when the process is completed.
- Process Characteristic: the process control that ensures the Product Characteristic is achieved by the process. It may be shown on manufacturing drawings or specifications, such as operator work instructions or set-up instructions. It can be measured while the product is being made, for example time, temperature or pressure.
- Item is the characteristic's number, and Description is its text. For example, Product Characteristic Item and Product Characteristic Description.
Why one row can't hold both
Each row is linked to a single characteristic, either product or process. If an import file has values in both the product and the process characteristic columns of the same row, that row is marked invalid and is not imported.
Where to enter them
- Put each characteristic on its own row: one row for the Product Characteristic, and a separate row for each Process Characteristic that controls it.
- In the AIAG & VDA PFMEA Form C (Standard) templates, enter Product Characteristics in 2b. Product Characteristic Item and 2c. Product Characteristic Description, and Process Characteristics in 3b. Process Characteristic Item and 3c. Process Characteristic Description, under Function Analysis (Step 3).
- Under Structure Analysis (Step 2), another column is also numbered 2b: 2b. Process Step :: Name of Focus Element. It holds the name of the process step, not a characteristic. Likewise, 3b. Process Work Element :: Description holds the work element description, not a Process Characteristic.
How characteristics reach the Control Plan
Core View brings the Process Flow, PFMEA and Control Plan together in one view. The Process Flow and Control Plan have the same Product Characteristic Item/Description and Process Characteristic Item/Description columns, so a characteristic you enter on a row is carried into those views.
Tip: Save characteristics you use often in the Reusable Library. You can then select them in these columns instead of retyping them. When a library record changes, every worksheet that uses it gets an alert, and the worksheet owner accepts or rejects the update.