matrix Management Consultants

Scheduling is Tradeoffs

One of the advantages of a MICRO TRIM® system is that it is truly a decision-assist workstation. It allows planners to run a problem or set of problems many different ways; until they find a solution applicable for the current operating conditions.
Minimizing trim loss, or maximizing salable production, is normally the primary goal of scheduling. However, there are some operating environments and restrictions that will not allow schedules based only on trim loss; and other goals will have to be considered in a good schedule. When this is the case, tradeoffs must be made, and emphasizing one goal will usually have a significant effect on the other goals. Ultimately, what is considered a good schedule will be in the eye of the beholder:

  • Management wants to maximize machine utilization and control over/under runs.
  • Marketing wants to meet the customers' requested ship dates and accommodate last minute requests for changes.
  • Production wants to minimize setups by reducing the number of patterns.
  • Shipping wants to minimize open orders, meet customer ship dates, maintain continuity by order / item, and control distribution costs.
  • Finishing wants all multi-pack rolls side by side when they arrive at the wrapping station.
These usually represent conflicting goals and influence the way a set of orders can be scheduled. Table 1, highlights ten different solutions for the same problem, and demonstrates the various tradeoffs that can be made when generating a schedule.

Table 1: COMPARISON SUMMARY (1)

1. Detail backup of data and reports are available for all solutions.
2. Shipping Performance  represents the number of open patterns after an order starts production. Numbers are shown for all orders and the first ten orders by priority.

  • The "best" solution for trim loss is Trim.
  • The "best" solution for patterns is Trim and Patterns. The tradeoff is simply whether or not eliminating 5 patterns is more valuable than eliminating 156.5 inches of trim loss.
  • In most cases either Trim, patterns and Shipping or Trim, patterns and Deviations will probably be selected; both provide a better balance of the goals

What is important, is that with MICRO TRIM® the user
can efficiently run alternate solutions; before making a selection.