One primary objective for introducing changes to the existing processes with the transition to the PLM environment will be to ensure consistency, discipline and control on the flow of data from Design to Manufacturing. This data flow, under Change Management control, will authorize manufacturing logistical actions. Automotive, Manufacturing, High Tech and Aerospace industries have widely adopted Engineering Change Management processes. Engineering Changes (EC’s) define parts release, revision and obsolescence which drives parts planning, acquisitions and dispositions. Knowing the EC level will help us isolate technical problems to dates and levels to minimize costs of identifying and fixing problems in the field. We know who has what, when it was built, and what is in each and every machine that is built. EC’s will provide a clear and precise historical record on all product programs, down to the individual part numbers.
Engineering Changes are the vehicle for releasing the product (item/BOM). An engineering change will establish or modify the basic records (part identification, content, usage) and reference the technical data, such as prints, drawings or CAD/CAM data. The release of technical data and records information should be concurrent. Usually, groups of parts to be designed and released at the same time are grouped into ECs.
The bill of material is a dynamic document, reflecting the dynamic nature of products. Products change and evolve, getting better. Changes to the bill-of-material can be a controversial topic. The problem with engineering changes is really several problems disguised as one. For a start, the basic problem is the volume of changes. One or two changes a year wouldn't amount to any problem at all. Dozens, or even hundreds, of engineering changes a month adds up to a nightmare when neither justified, nor
managed properly. Finally, bill-of-material changes, when handled incorrectly, tend to generate a lot of problems, which are usually blamed on something else.
Engineering changes are, as a rule, tough to control and hard to communicate to everyone who needs to know. Many companies do not have the tools for planning and scheduling in place, so it doesn't matter how the bill-of-material changes are made. Perhaps the biggest reason people are against using an EC to control a product/part release is a lack of understanding about the impact those changes can have on the business. It's not always obvious that the visible problems on the shop floor are a direct result of mismanaging engineering changes. Here are just a few of the problems that can result from poorly managed changes:
1. Excess obsolete inventory: This happens all the time. There is inventory left over after the part has been obsolete. If changes are poorly managed, it is not unusual to see obsolete parts reordered.
2. Assembly, packaging or finishing shortages: You can't build it if you don't have the parts. Shortages often occur because we run out of one component before the new component was ready or had been delivered. When the bill-of-material is not current, the wrong material is scheduled.
3. Inefficient Production: When engineering changes are not properly managed, theproblem often doesn't surface until the last minute. Final Assembly discovers it is using Revision D. The latest engineering design is Revision E. The parts must be reworked or produced to the latest revision with zero lead time.
4. Missed delivery dates to customers: Only items on the bill-of-material can be scheduled. When the bill is not updated with the latest engineering changes, the wrong materials are scheduled and produced. The problem is usually discovered in the final stages of production, and that's too late.
5. Poor product quality: When the bill is not properly maintained, the latest product improvements from Product Engineering are not communicated to the factory floor.
6. Lack of configuration control: Product liability is a big issue facing industry. Failure to provide good control over the configuration of your product is the quickest road to failure.
7. Erroneous product costing: When the bill-of-material is not maintained properly, the product costs do not reflect what it actually costs to make the product.
The net result is that mismanaged bill-of-material changes result in major financial losses, and many companies don't even realize it. Time and time again, people who routinely handle their companies bills do not realize the cost implications in poorly managed changes. They don't monitor change costs, and, consequently, top management isn't aware that a problem even exists.
Conclusion
Competing in today's global market means getting new, innovative products to the market before the competition. By using the formal system and having an efficient product change management process which starts in the early stages of engineering, all of the documentation necessary to get into production can be justified, tested and released to manufacturing in a seamless fashion.
