Production Activity Control Chapter 11 Vollmann, Berry, Whybark & Jacobs
Production Activity Control PAC in the MPC System Shop Floor Control Vendor Scheduling Production Activity Control Techniques Basic Data/ lead time management Gantt Charts Priority Scheduling Finite Loading Process Design Impact on Scheduling Batch Manufacturing – Work Orders Repetitive Manufacturing – JIT
Production Activity Control in the MPC System
Figure 11.2 Example
Fig. 11.3 Routing Data and Operation Setback Chart
Time concepts: Lead time elements Run time: operation or machine time per piece * lot size. Setup time: time to prepare the work center, independent of work center. Move time: delay waiting to be moved + move time from center to center. Queue time: time spent waiting to be processed (depends on work load and schedule).
Lead time management Lead time vs. WIP Substitute information for inventory Changing lead time information: Systematically through DBS Recalculate using various methods Lead time Queue time issues
Priority Sequencing Rules A rule for what job to process next: First Come, First Served Shortest Operation Next Earliest Due Date Order Slack (least): (Time Remaining until Due Date – Sum of Remaining Setup and Run Time) Slack per Operation (least) Critical Ratio: (Due Date-Now)/(Lead Time Remaining) (least) ________________________________________ Lead Time Remaining includes setup, run, move and queue time for all remaining operations.
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