Engineers, purchasing professionals and others often submit schematics and drawings in paper form without a CAD file. Some manufacturing companies will insist on a CAD file and will not quote or take an order without a CAD file. Other shops don't need or use CAD files but these shops are often fairly small and have longer lead times because they might be using manual machines instead of CNC. So, a problem for engineers and professionals is a case when they need components, assemblies or tooling made quickly but they don't have a CAD file.
Another problem can be CAD file delays. For example, suppose I have a drawing but my supplier wants a CAD file so I go to my co-worker or assigned person to generate the CAD file and days go by without results. This can be a major cause of delay. Often times, after waiting for a long time for the CAD file and then sending it to the supplier, the engineer finds out that the format is unacceptable and they're back at square one, waiting for the CAD specialist or co-worker to help.
There is a solution to all of these problems. The key is finding a contract manufacturer to partner with and build trust with that supplier. For example, I & M CNC Machining receives drawings and even sketches without CAD files and is still able to quote and make the parts quickly. What is the secret? I & M CNC, like other manufacturers, actually takes the time to make its own CAD files, if needed, based on the customers paper drawings when CAD files are not available. We do this so that the information can be quickly and easily checked and programmed using CNC. How is it possible to make drawings and parts in just a few days? At some companies, the day does not end at 5:00 pm. When there are tasks at hand, some companies stay open all night and get the job done while not cutting corners.
Formatting issues are not very challenging, once you have a great supplier you are partnering with. Sure, there could be a slight learning curve at the very beginning but in most cases a capable contract manufacturer will be able to read your file formats. DXF is the best format but other popular formats are DWG and SLD. One should always submit a layout version in PDF whenever possible, along with a model file if it is handy. What to look for when searching for a C.M. partner? After finding a supplier or two and giving them a small P.O., look for these signs:
Delivery on time?
Any price changes or lead time changes at last minute?
Paperwork correct (address, names, CoC, etc.)?
If you answer "no" to more than 1-2 of the above criteria, I would keep looking for a different manufacturer. If the supplier misses on only 1 or 2 of the above criteria, you can communicate with them and tell them what you expect and express your disappointment. Of course, you need to have plenty of notes on your drawings, PO's and specifications so that the supplier knows what is on your mind.