Operations Management Operations Scheduling Manufacturing Execution Systems Equipment Scheduling Work Centers Priority rules Johnson’s rule Backward / Forward scheduling Workforce Scheduling MBA.782.Operations.Scheduling

Work flow is driven by a schedule Oper. Sched. Manufacturing Execution Systems Work flow = Cash flow Work flow is driven by a schedule ____ % of time actually working; ____ % of time waiting in queues Schedule equipment and workforce MBA.782.Operations.Scheduling 3

Becomes exceedingly complex because.... Oper. Sched. Equipment Scheduling Becomes exceedingly complex because.... Unpredictability of demand for all resources Variability of throughput times Tradeoffs among: Utilization of people and equipment vs. Work in Process vs. ability to meet promised delivery dates MBA.782.Operations.Scheduling 3

where a particular type of work is done. Equip. Sched.. Work Centers A work center is an area in a business in which productive resources are organized and work is completed. where a particular type of work is done. Finite / infinite ____________ backward / forward _____________ machine and/or labor ___________ MBA.782.Operations.Scheduling 3

___________ for the resource of interest Equip. Sched. Definitions Queue time ___________ for the resource of interest Flow time = operation time + queue time time for a job to _______________ the process Lateness = ( Flow time - Due date ) + Completion time (aka, ______________ ) finish time of last job - start time of first job MBA.782.Operations.Scheduling 3

Meeting ____ ______ of customers or downstream operations. Equip. Sched. Schedule Performance Measures Meeting ____ ______ of customers or downstream operations. Minimizing the flow time the time a job _________ in the process Minimizing work-in-process inventory. Minimizing _____ ______ of machines or workers. Maximize machine utilization MBA.782.Operations.Scheduling 9

Allocating orders, equipment, and personnel. Equip. Sched. Scheduling Activities Allocating orders, equipment, and personnel. Determining the ____________ of order performance. Schedule jobs as a _________ with process stages back to back. Re-schedule every day. MBA.782.Operations.Scheduling 5

Used for n-Jobs on One Machine Local Priority Rules Equip. Sched. Priority Rules and Techniques Used for n-Jobs on One Machine Local Priority Rules schedule jobs according to their effect on the _____________________ workstation Global Priority Rules sequence jobs according to their effect on ____________ work requirements MBA.782.Operations.Scheduling 9

Suppose these four jobs arrive for processing on one machine: Local Priority Rules First Come, First Serve (FCFS) Suppose these four jobs arrive for processing on one machine: MBA.782.Operations.Scheduling 9

The job with the shortest processing time is processed first Local Priority Rules Shortest Operation Time (SOT) The job with the shortest processing time is processed first MBA.782.Operations.Scheduling 9

Schedule job with smallest slack first Local Priority Rules Slack Time Remaining (STR) Schedule job with smallest slack first MBA.782.Operations.Scheduling 9

MBA.782.Operations.Scheduling

Sequence: ____ , ____ , ____ , ____ Global Priority Rules. Critical Ratio (CR) Sequence: ____ , ____ , ____ , ____ MBA.782.Operations.Scheduling 9

Sequence: ____ , ____ , ____ , ____ Global Priority Rules. Dynamic Slack / Operation Remaining Sequence: ____ , ____ , ____ , ____ MBA.782.Operations.Scheduling 9

Job A Job B Job C Jobs (N = 3) Saw Drill Oper. Sched. Johnson’s Rule Used to schedule n-jobs through 2 sequential machines Jobs (N = 3) Saw Drill Job A Job B Job C © 1995 Corel Corp. © 1995 Corel Corp. MBA.782.Operations.Scheduling

Once a job is scheduled, eliminate it. Oper. Sched. Johnson’s Rule All jobs are to be listed, and the time required on each machine is shown. Select the job with the shortest activity time. If the shortest time lies with the first machine, the job is scheduled first; if with the second machine, the job is scheduled last. Once a job is scheduled, eliminate it. Apply steps 2-3 to the remaining jobs, working toward the center of the sequence. MBA.782.Operations.Scheduling

Jobs to be sent through a 2-machine sequence... Oper. Sched. Johnson’s Rule Jobs to be sent through a 2-machine sequence... Job Saw Time Drill Time A 5 2 B 3 6 C 8 4 D 10 7 E 7 12 MBA.782.Operations.Scheduling

schedule the ____________ possible starting time Oper. Sched. Forward and Backward Scheduling Forward Scheduling schedule the ____________ possible starting time due dates determined by internal scheduler Backward Scheduling determine the _____________ possible starting time for externally set due dates MBA.782.Operations.Scheduling 21

Oper. Sched. Forward and Backward Scheduling MBA.782.Operations.Scheduling 21

Oper. Sched. Forward and Backward Scheduling MBA.782.Operations.Scheduling 21

forecasted staffing levels Oper. Sched. Workforce Scheduling in Services Need to know forecasted staffing levels specific skills needed during the time-frame work-hour constraints Consecutive days-off requirements methods exist to provide the _____ schedule Complex scheduling situations computer programs used to find ______________ schedules, given many constraints MBA.782.Operations.Scheduling 21

Oper. Sched. Scheduling Consecutive Days Off Objective find the schedule that minimizes the number of five-day workers with two consecutive days off, subject to the demands of the daily staffing schedule Procedure given the total number of workers needed each day, create a schedule by adding one worker at a time MBA.782.Operations.Scheduling 21

Oper. Sched. Scheduling Consecutive Days Off MBA.782.Operations.Scheduling 21

Concepts / Terminology Review Lecture notes Recommended Problems Topic Title Chapter Wrap-Up Read Chapter 15 Concepts / Terminology Review Lecture notes Recommended Problems MBA.782.Operations.Scheduling

Principles of Work Center Scheduling 1. There is a direct equivalence between work flow and cash flow. 2. The effectiveness of any job shop should be measured by speed of flow through the shop. 3. Schedule jobs as a string, with process steps back-to-back. 4. A job once started should not be interrupted. MBA.782.Operations.Scheduling 18

Principles of Job Shop Scheduling (Continued) 5. Speed of flow is most efficiently achieved by focusing on bottleneck work centers and jobs. 6. Reschedule every day. 7. Obtain feedback each day on jobs that are not completed at each work center. 8. Match work center input information to what the worker can actually do. MBA.782.Operations.Scheduling 19

Principles of Job Shop Scheduling (Continued) 9. When seeking improvement in output, look for incompatibility between engineering design and process execution. 10. Certainty of standards, routings, and so forth is not possible in a job shop, but always work towards achieving it. MBA.782.Operations.Scheduling 20