We’ve helped several small companies move from a “job-shop” approach to a more systematic way of manufacturing. Usually, this is a dramatic improvement for everyone involved. There are lots of people happy to sell you software to run your plant, and you should use one of those if possible. But just doing the things on this list will be a big help, and if you get these things worked out, then going to a full MRP system will be an easier step.
Suggestions for moving manufacturing from memory-based system to paper-based or computer-based system
- Every part needs a part number. Even purchased parts that already have a supplier’s part number. The numbering system you choose can have “significance”, where the number has meaning, like using 516x2HH for a 5/16” x 2” hex-head bolt, or it can just be a non-significant number, like 105446, that has no meaning. I feel that non-significant numbers are much easier to deal with in the long run, especially when you grow to point that all the numbers aren’t created by the same person. A six-digit number is enough that you won’t run out, and they are easily remembered. But whatever system you create, stick with it.
- Every part needs a Name or Description. If you create some rules and systems for how you name parts, they will be easier find in an alphabetical list. It’s easier to make the number dumb and the description smart than it is to try to create a significant numbering scheme.
- Almost every part needs a drawing. If you are ever going to sell one as a service part, it definitely needs a number and drawing. Welded subassemblies that get later get welded into a larger assembly don’t have to have a drawing, but can have one if it makes someone’s job easier.
- The definition of a “drawing” needs to be pretty loose—any document that describes the part completely enough that it can be made (or ordered from a vendor) by someone who’s never seen it before is an adequate drawing. Some parts, like nuts and bolts, are so simple that a five or six word description can serve as the “drawing”, and they don’t need their own sheet of paper or file. A hand sketch on paper with correct information is a lot better than a CAD drawing that doesn’t exist yet. Drawings for purchased parts can be just the part number, description, supplier, and supplier p/n, or can be cut and pasted from suppliers websites.
- A master list or “ledger” of all part numbers needs to be maintained. Copies can be anywhere but there needs to be one master that is always up to date.
- A cross-reference list of your part number to Vendor part number would be very useful. Again, anyone that needs it should have a copy, but there should be one master list.
- There are lots of other lists that make various jobs easier. Common ones are a list of standard hardware like nuts and bolts, a list of standard bearings, a list of hydraulic hoses, etc. Having these and keeping them up to date will keep you from accidently creating two part numbers for the same thing.
- Intermediate steps in the manufacturing process usually do not need part numbers. For instance, a part that is cut to length, then drilled, then bent, doesn’t need a different number for each stage. A part that is purchased, then modified in some way needs a number for the purchased part, and a number for the finished part.
- A very simple “work order” system should be worked out. Many company’s systems have vast amounts of useless information in the paperwork and are very confusing to the fabricator. The only information that really needs to be on the work order is some sort of identification number (Work Order #), the part number, the quantity needed, and a due date. A copy of the drawing should be attached to the work order, and when the order is completed, the paperwork can be turned in to signify that it is complete.
- A bill of materials (BOM) listing all the parts needed to build a machine is very useful. This can be used to generate a list of parts needed to produce a particular machine; items already in stock can be checked off and everything else can be ordered.
- When design changes are made, if the revised part can be used as a direct replacement for the old one, it can use the same part number. If not, it needs a new number.
- All of this can be done with paper or simple Excel spreadsheets, and work pretty well. If you get to where you’re building things that have hundreds of parts in the assemblies, you should start looking at manufacturing control software. If you’re designing with a modern 3D CAD system like SolidWorks, some of this organization is built into that already.