It might take two to four months from the time the idea is hatched until the time a vendor can be approached. The time is required to understand the requirements and to document them concisely in a form usable by a vendor or developer.

From a plant s viewpoint, the best scenario is a reasonably priced package that currently exists, that requires no customization, just parameter tuning and configuring. No programming, no extreme requirements for training, no hassles.

The types of systems described in the preceding chapter present special challenges to a factory. It is not reasonable for a single manufacturer, unless you are huge, to undertake the full development of a planning and scheduling tool. The cost and development effort is in the millions of dollars. The development time is years. It will be hard to obtain a return on the investment and you might end up looking for other plants to share the costs with or to license the tool. There are three other reasonable options for acquiring a software tool:

• Use one off the shelf, plug and play it.

• Tailor or customize a close match by working with the vendor or qualified third parties.

• Do it yourself, or with contract programmers, by utilizing a scheduling toolkit or software library as a starting point. While incurring some development costs and risks, hope that the majority of the messy stuff is already done.

As much as someone would like to create a custom tool or customize an...