Category Archives: Scheduling

Scheduling n Jobs on One Machine Let ux compare some of these 10 priority rules in a static scheduling situation involving four jobs on one machine. (In scheduling terminology. this class of problems is referred to as an “n job-one-machine problem.’ or simply The theoretical difficulty of this type of problem increases as.more machines are considered: therefore. the only restriction on n is that it

Schedule Evaluation Criteria The following standard measures of schedule performance are used to evaluate priority rules: 1. Meeting due dates of customers or downstream operations. 2. Minimizing flow time (also known as cycle time or throughput time), which is the time a job spends in the shop. 3. Minimizing work in process. 4. Minimizing idle time of machines and workers

Priority Rules for Allocating Jobs to Machines The process of determining which job is started first on a particular machine or work center is known as sequencing or priority sequencing. Priority rules are the criteria by which the sequence of job is determined. These can be very simple. requiring only that jobs be sequenced according to one piece of data. such as processing time, due date. or order of  arrival

The Flow Pattern of Jobs through the Shop Exhibit 12.2 shows the various possible flows of jobs through a job shop. In some job shops. all jobs follow the same pattern; in others. the pattern is purely random. Most job shops fall somewhere in between these two extremes’: Because of the apparent lack of organization, the flow of material through a job shop is often described as jumbled flow.

The Ratio of Skilled Workers to Machines Job shops can be classified as either machine-limited or labor-limited, depending on whether the workers outnumber the machines  or vice versa. In addition. jobs may be classified as labor-intensive or machine intensive  depending on how much of the job may be performed using automated processes.

The “Machinery in the Shop The scheduling problem is also dependent on the number and variety of the equipment or “machines” in the shop. Further, as these “machines” become smarter and are more capable of multitasking. the task of scheduling becomes more complicated.

Elements of the Job Shop Scheduling Problem a hospital may be organized by Function: the examination rooms are separate from the x-ray room, which is separate from the waiting room. Depending on the needs of the patient, different jobs are performed at different physical locations within the ER, and in some cases. at locations within the hospital other than the ER. A riding academy not only boards and exercises

Scheduling in a Job Shop A schedule is a timetable for performing activities, using resources, or allocating facilities. The purpose of operations scheduling in a job shop is to disaggregate the master production schedule (MPS) into time-phased weekly. daily, and/or hourly activities-in other words. to specify in precise terms the planned workload on the production process in the very short run. Operations cont

A job shop is a functional organization whose departments or work centers are organized around particular processes that consist of specific types of equipment and/or operations, such as drilling and assembly in a factory, and scanning and printing in a computer laboratory. A good example of a job shop in a service environment is a hospital, which has designated areas for blood tests, x-rays, and radiation tre

SCHEDULING PRIORITIES AT TAX TIME “Every year it’s the same thing. We have our corporate clients that need their tax returns completed by March 15 and our individual clients that need their personal income tax returns done by April 15, but it seems that whatever plan we have in place with respect to scheduling the work, these three months of February, March, and April are still crazy.”  Ron