Hi Jim, First, I believe that tracking process performance prior to the touch-up operation is very important. Mainly because ruducing the amount of touch-up, reduces the amount of handling and manual operations that assemblies go through. In order to do this you must record the data that is available in your post-process inspection. An effective way to track these defects is with a ratio of defects to the number of opportunities to produce defects. A very simple example would be an assembly with 400 solder connections that you were producing a quantity of 100. During post-wave inspection for example, you find a total of 240 areas that require "touch-up" (defects). This comes out to an average of 2.4 defects per board, and likely a yield of 0%-10%. Obviously the yield info tells you very little about the actual frequency of defects the process produces. So a better way to look at it is to multiply 400 opportunities to produce defects, times the number of boards built (100) = 40,000 opportunites. The result is 240 defects produced out of 40,000 opportunities. The result is 240 divided by 40,000 or .006 DPO (defects per opportunity). In the industry, most companies base their performance goals on the number of defects per million opportunities. So now take .006 times 1million to get 6000 DPM (Defects per million opportunies). Some also use PPM to describe the same ratio. From here you can set new goals for your "process" and not just individual assemblies. For now you have a number that represents your "rate" of producing defects. Now try to bring that number down. Formula summary: A= Number of defects found in a "Lot" B= Number of Opportunites To Produce Defects Per Assembly (Often the number of individual solder connections, yep ya got go count em) C= Number of Assemblies per "Lot" DPM=A/(B*C)*1000000 Now that you have a way to track current performance and progress towards goals, the most important thing is HOW you will reach those goals. This is where commitment to make quality products comes in. It is beneficial to now make Paretos of the defect types and defect locations. Shorts and Opens are likely to vague as descriptions. You will want to learn to identify Insufficient solder, Cold Solder, Open due to misalignment etc, etc. also track the locations of these defects. For Example: Insufficient solder at U1-7 (Pin 7 of IC U1) A matrix of check marks can be an easy way for the post-process inspectors to record this data. As they put in arrow on the Assembly for touch-up, they can use a matrix worksheet to record the defect type and location. Here is a crude sample Post Wave Inspection Log Assembly Number______ Lot Quantity ______ Insufficient Solder Cold Solder Missing Part Solder Bridge Damaged Part R1 XX X R2 R3 XXX C1 C2 C3 U1 U2 U3 6 (means pin 6) Hope this helps, Sean ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################