Chapter 15 - Scheduling - Operations Management Lecture Notes

These vocabulary flashcards cover standard scheduling concepts, various priority rules, performance measures, and management philosophies like OPT and TOC extracted from Chapter 15 of Operations Management Seventh Edition.

Flow operations

Processes designed to handle high-volume, standard products within a system.

Routing

Provides information about the operations to be performed, their sequence, the work centers, and the time standards.

Job shop operations

Low-volume operations designed for flexibility, often involving customized products or services with higher margins.

Gantt Chart

A visual representation of a schedule over time, developed in the early 1900s by Henry Gantt.

Load chart

A type of Gantt chart that illustrates the workload relative to the capacity of a resource.

Progress chart

A type of Gantt chart that illustrates the planned schedule compared to actual performance.

Infinite loading

A loading method that ignores capacity constraints but helps identify bottlenecks in a proposed schedule to enable proactive management.

Finite loading

A loading method that allows only as much work to be assigned as can be done with available capacity.

Forward scheduling

A scheduling method that determines the earliest possible completion date for a job.

Backward scheduling

A scheduling method that starts with the due date for an order and works backward to determine the start date for each activity.

Due date

The specific time when a job is supposed to be finished.

Slack

The amount of time a job can be delayed and still be finished by its due date.

Input/output control

A capacity-control technique used to monitor work flow at individual work centers.

Operation sequencing

A short-term plan of actual jobs to be run in each work center based on available capacity and priorities.

Queue

A waiting line for jobs needing to be processed.

Priority rule

A rule used to determine the priority of jobs at a work center.

Local priority rule

A priority decision based on jobs currently at a specific work center.

Global priority rule

A priority decision based on information that includes the remaining work centers a job must pass through.

First come, first served (FCFS)

A priority rule where jobs are processed in the order in which they arrive at a machine or work center.

Last come, first served (LCFS)

A priority rule where the last job into the work center is processed first.

Earliest due date (EDD)

A priority rule where the job due the earliest has the highest priority.

Shortest processing time (SPT)

A priority rule where the job that requires the least processing time has the highest priority.

Longest processing time (LPT)

A priority rule where the job that requires the longest processing time has the highest priority.

Critical ratio (CR)

A priority rule where the highest priority is given to the job with the smallest ratio of $\frac{\text{time remaining until due date}}{\text{processing time remaining}}$.

Slack per remaining operations (S/RO)

A priority rule where highest priority goes to the job with the least slack per remaining operations, calculated as $\frac{\text{slack}}{\text{remaining operations}}$.

Makespan

The time it takes to finish a batch of jobs, calculated as $\text{Completion time for final job} - \text{Start time for first job}$.

Job flow time

A measure of responsiveness calculated as $\text{Job completion time} - \text{Time the job was first available for processing}$.

Average number of jobs in system

A measure of responsiveness and work-in-process inventory calculated as $\frac{\sum \text{job flow times}}{\text{number of days to complete batch}}$.

Job lateness

A measurement of whether a job is completed ahead of, on, or behind schedule.

Job tardiness

A measurement of how long after the due date a job was completed.

Mean Flow Time (MFT)

The average time jobs spend in the system, calculated as $\text{MFT} = \frac{\sum \text{job flow times}}{\text{number of jobs}}$.

Johnson’s Rule

A technique for minimizing makespan in a two-stage, unidirectional process.

Optimized production technology (OPT)

A scheduling and capacity planning system introduced by Eli Goldratt that focuses on bottlenecks.

Throughput

The quantity of finished goods to be sold.

Transfer batch

The quantity of items moved at the same time from one resource to the next.

Process batch

The quantity produced at a resource before switching to another product.

Theory of Constraints (TOC)

A managerial philosophy and extension of OPT suggesting that a system’s output is determined by its constraints.

Tibrewala, Philippe, and Brown technique

A technique for scheduling a seven-day operation giving each employee two consecutive days off.