Blueprint accuracy and document control

Customer blueprints (raise your hand if you know why they are called ‘blue’) are part of the contract that accompanies every order that is placed by a customer. Inaccuracies, ambiguities, running revision changes and verbal modifications/undocumented changes can lead to very unhappy situations with our customers. At Fabcor we have systems in place to ensure that any known modifications are documented in the course of running an order. Most of our customers have very rigorous document control and revision change procedures that ensure 100% accuracy on all prints that are released for production – these orders make everybody very happy. We have a few customers that do not have these controls in place and when these orders are processed we do everything that we can to make sure that they get the parts that they want – which may not be the parts that are on their prints. Here are a few examples of what I would call compromised document control:

  • Same Part number, different parts at the same revision level – In this case changes were made to the print but the revision level was not changed. When the order comes into our shop it will be treated as a repeat order and built to the original revision because we have no way of knowing that the part was changed.   If the revision level changes on the PO then our system tells us that the part has not been run at the new revision and we have a process in place that checks the prior revision with the new revision so that programming changes can be made. Also, ongoing production and inventory issues are addressed.
  • The same part ordered with 2 different part numbers – This usually occurs when customers order by ‘description’. Typically they don’t have a rigorous doc control system and they send in an order to make a bracket using ‘bracket’ as the identifier or some other descriptive term. They order the part several times with several different descriptors, for example ‘large bracket’ or ‘adaptor bracket’ and each time it is ordered it is treated like a new part because the ‘part number, i.e. descriptor’ doesn’t exist on our system.  This leads to a lot of extra work for us because we have to make new work order routings, new programs, new set ups sheets, etc. when in fact all of these things exist for the part.
  • Verbal Changes without formal documentation – Changes often come from customers via e-mail or telephone and with no formal documentation to follow up the change. In this case the prints are ‘redlined’ and the order continues through the shop with the idea that the part will get a new revision at some time in the future. Sometimes this happens and sometimes it does not. Since we do not have control over our customer’s prints we have to make the changes on our Master document and operate as if the changes will never be made. They are carefully and clearly marked in red and initialed and dated at the time they are made, however this can cause ambiguity because our prints do not match what the customer is holding.  QC could reject the parts and then we would have to dispute the rejection, etc. – not a good situation for us or our customers.
  • Errors on the prints – With parametric CAD systems so prevalent prints are usually very accurate. However, we still get errors due to round off, manual adjustments that are incorrect or misalignment during the modeling phase of the design.  At Fabcor we will fit check and correct (with customer permission) any parts that are not fitting properly in production when we know that they mate together with other components of an assembly. Our foreman and QC Manager work together to make the part function properly for our customer needs. It can slow things down sometimes but it avoids costly rework and scrapping of parts.


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