Job Shop Scheduler Overview

In the Production Scheduler module production orders are manipulated, whereas Enterprise Planning handles production orders. The scheduler covers the very near future, up to a few weeks. The objective of the scheduler is to minimize the consequences of disruptions during production such as:

• Additional sales orders accepted within the agreed lead time
• Late material deliveries
• Machine breakdowns
• Production backlog

To achieve this, the scheduler:

• Schedules work only after materials are available
• Prioritizing and sequencing work according to specifically defined rules
• Schedules work on bottleneck machines against finite capacity

The objective of minimizing the maximum lateness means that the scheduler strives to keep the highest lateness of all the production orders as low as possible.

Lateness is defined as the time which is short between the scheduled finish date of an order in relation to the due date at which the production order must be completed in order to be on time for its upstream demand.

The algorithm for the minimize maximum lateness objective is the Earliest Due Date algorithm. The Earliest Due Date algorithm is based on the priority rule which states that the operation with the earliest due date should be scheduled first.