Exam 16: Short-Term Scheduling

Given the following chart of jobs assigned with Johnson's rule,suppose that all the jobs (A,B,C,etc)could be evenly divided into two tasks (such as A1 and A2,B1 and B2,etc).Suppose job B is divided into jobs B1 and B2,each with a body work time of 4.5 hours and a paint time of 2 hours.How much is makespan reduced by this splitting of B?

What is a method of input-output control that uses a system of cards to limit the amount of work at a work center and also to control lead time and monitor backlog?

Complete the table; find average lateness,average completion time,and average number of jobs in the system.Assume all durations are in days and that the jobs are processed at the shop in the order that they arrive (A then B then C then D).

Which of the following is a limitation of rules-based dispatching systems?

With forward scheduling,jobs are scheduled as late as possible within the time allowed by the customer due dates.

At Morgan's Transformer Rebuilding,five jobs are ready now for dispatching to a machine center.The processing times and due dates for the jobs are given below.Use earliest due date to sequence the jobs,and calculate the average completion time,the average job lateness,and the average number of jobs in the machine center.

If an assignment problem consists of 5 workers and 4 projects:

When a set of jobs must pass through two workstations whose sequence is fixed,________ is the sequencing rule most commonly applied.

In services,the scheduling emphasis is usually on staffing levels,not materials.

The constant work-in-process (ConWIP)card aids input-output control by limiting the amount of work in a work center.

Jack's Refrigeration Repair is under contract to repair,recondition,and/or refurbish commercial and industrial icemakers from restaurants,seafood processors,and similar organizations.Jack currently has five jobs to be scheduled,shown in the order in which they arrived. (a)Complete the following table.(Show your supporting calculations below). (b)Which dispatching rule has the best score for flow time? (c)Which dispatching rule has the best score for work-in-process (jobs in the system)? (d)Which dispatching rule has the best score for lateness?

Dispatching rules are typically judged by four effectiveness criteria: average completion time,utilization,average number of jobs in the system,and average job lateness.

Which critical ratio value implies that a job is already late?

Which of the following considers process capacity when scheduling?

Short-term schedules are prepared:

A work center had actual input of 280 hours and actual output of 270 hours.What is the change in backlog?

Which of the following is NOT a key direct benefit from effective internal or external scheduling?

In the sequence of decisions that affect scheduling,________ is (are)the immediate follower(s)of the master schedule (or master production schedule).

Compare short-term scheduling at process-focused,repetitive,and product-focused facilities.

Using LPT priority would result in what sequence for Jobs A,B,C,and D if their process times are 4,6,5,and 2 respectively?