Hi Sandy,
Welcome to the Journey. You have passed the first hurdle by recognizing that your
PFMEA?s are useless and you are willing to start over with an improved process. I was lucky enough to be in your position years ago with a very good company who wanted to be the best. Within a few years they became world leaders in cost and quality for injection molders (~2.3 PPM while producing 220MM pieces per year consisting of 1400 different part numbers using 80 different compounds.) The
APQP Teams could produce a new, custom PFMEA within 2 hours. It took a while to get there, but it was not an overwhelming task.
First, study the AIAG APQP Manual?s Supplement A - EQUIPMENT: SET-UP DOMINANT PROCESS: The process is highly capable and stable, therefore set-up is major variable impacting product variation. It explains the concept behind a ?Process Controlled? type of PFMEA which injection molding falls under.
Next, identify a standard, common, higher volume part that your company produces. Begin with a listing of the parts requirements from the blueprint(s), engineering specification(s), customer?s quality, shipping, & purchasing manual(s). Identify any and all requirements. While useful for the part layout PPAP requirement you do not need to identify all of the molding dimensions as they are controlled by the mold itself.
Create 5 columns in a spreadsheet labeled: 1) Process step, 2) Process Requirement, 3) Requirement ID, 4) Product Requirement and 5) Process Requirement. Place that list produced above in the 4th column. Now, across the top place the process steps that are required to produce the product, everything from receiving material to setting the mold to 1st piece inspection to last piece inspection to shipping (on the truck) [A shipping requirement may be that it shipped via ?air-ride? truck.] You are producing a level 3 QFD characteristics matrix. At each intersection of requirement and requirement producing process place the process step ID in the 1st column; the general Process Requirement being produced at that Process step in the 2nd column; a Requirement ID (print balloon number, Engr. Spec ID, etc.) in the 3rd column.
The 5th column is where you place the specific processes, forms, set-up parameters, etc. to produce the product requirement(s) associated with that particular step. Wa-la, you have now produced the first 5 columns of the AIAG Form-H PFMEA for Process/Set-up dominate processes. [Note: if your company does not have a predetermined PFMEA package, I would begin with MS Excel as it is flexible and allows you to understand your company?s process before a large investment in a fixed package. Systems2win?s FMEA2 and other templates are an excellent starting point for training in proper techniques while performing activities.]
You will identify molding process/product requirements such as: Shorts, Flash, "(Material) Contamination", Splay, Warpage, "Stress Cracks / Knit Lines", "Grease or Mold Protectant", "Broken or Pushing Ejector Pins", Gate Vestige, Blisters, Breakage, Strings, ?Delamination?, Sinks/Voids, Gas Burn, Wrong Material, Color, Frost, Shine, Texture, Scratches, Scuffs, White Marks, Gate Blush, Knit Lines, Correct Date Code, etc. depending upon the type of parts you produce.
Hot runner vs. cold runner, re-grind amount and mixing process, machine set-up and documented adjustments, compound dryness, etc. all effect the molding process step. There are literally hundreds of items to identify and control.
Next, you must conceive the concept of a Legacy / Master / Standard PFMEA. What are common and specific caused of failure, prevention and detection. Common are reused in future PFMEA?s. Keep them in your Legacy / Master / Standard PFMEA for future use.
The next big step is working on your Process error symptoms, 5-Why, CAR/PAR reporting system to qualify occurrence and detection levels.
There are many other tricks to produce Process Step diagrams, PFMEA?s, and Control Plans simultaneously with all product knowledge in a couple of worksheets (with Excel 2007 & above), with the help of a few macro buttons. You will need to conceive of variable substitution in your requirement and control ?cells? for that level of integration. The company described above did this using Excel 2000 and paper so it can be done without expensive tools.
Good Luck on your Journey.