BUS606: Operations and Supply Chain Management

4a. Describe typical scheduling and control functions, such as determining the number of jobs to assign to a machine in manufacturing or scheduling daily and hourly work times in services personnel

• How are scheduling problems described?
• How does a dedicated machine in manufacturing differ from a parallel machine?
• What parameters make up the task set?
• What criteria constitute the optimality criteria?
  

Scheduling problems in manufacturing consist of three parameters: (1) the processing (machine set), (2) the task set, and (3) the optimality criteria.
 
In production systems, machines are either dedicated or parallel. Dedicated machines can be further defined as flow-shop, open-shop, and job-shop. Parallel machines can be further defined as identical processors, uniform processors, and unrelated processors.
 
The task system corresponds to the applications for manufactured goods. Each task can be described by several parameters: number of operations, execution time, ready time, deadline, resource requirements, and weight.
 
The final parameter is the optimality criteria, consisting of schedule length, maximum lateness, mean flow time, and mean tardiness.
 
To review, see Scheduling in Manufacturing Systems: The Ant Colony Approach.
 

4b. Explain how shop floor layout factors into scheduling processes and using resources efficiently 

• What is plant layout, and what are the objectives of an effective plant layout?
• How do the types of plant layouts differ?
• What are the advantages and disadvantages of each different plant layout?
  

In plant layout, we look at the arrangement of equipment, material, and staffing to achieve as high productivity as possible. There exist many objectives of good plant layout, including reducing bottlenecks in the production process, minimizing employee movement, and increasing the flexibility for future changes in product design, among others. Four layout categories exist: process layout, product layout, combination layout, and fixed-position layout.
 
In a process layout, machines are arranged according to their function. In product layout, operations are performed in a sequence, and machines are organized based on that sequence. In a combination layout, the plant is arranged as both a process and a product layout – using both layouts' advantages. In a fixed position layout, the product remains stationary, and the production moves around the product – think airplanes and shipbuilding.
 
Each of these four layouts has advantages and disadvantages. Make sure you understand all of these and think about what products are made through each type of layout.
 

4c. Use priority rules to determine the optimum number of jobs and machines to schedule 

• What is production scheduling?
• What are some common priority rules to use for scheduling?
  

Production scheduling consists of the activities performed in manufacturing to manage and control the execution of the production process. A schedule describes in detail (in terms of minutes and seconds) which activities must be performed and how resources should be used to satisfy the plan. Detailed scheduling involves determining the allocation of machines to competing jobs over time, subject to constraints.
 
Because machines can handle one task at a time, priority rules must be set in place as part of the scheduling process. Some common priority rules include earliest due date, where jobs are scheduled by the earliest due date of competing orders; longest processing time, where scheduling assigns the highest priority to the jobs with the longest processing time; shortest processing time, where the highest priority is given to jobs with the shortest processing time, first-come, first-serve, and preferred customer order.
 
To review, see Job Sequencing and Priority Rules.
 

4d. Analyze service industries in terms of personnel scheduling and estimating daily demand 

• What are the different methods we can use to schedule personnel?
• Can you think of service industries that would use these different scheduling methods?
  

Personnel scheduling is applicable in many service industries, such as airlines, hospitals, and banks. Scheduling personnel should balance the employee's needs, the customer's, and the tasks involved. Scheduling conflicts or poorly arranged schedules can lead to a loss of motivation by the employees and fatigue, accidents, and mistakes (in the case of overscheduling personnel). Scheduling personnel in a small service organization might be easy, but as service organizations become large and complex, some scheduling methods are available for the organization to use. Scheduling must always conform to the workload pattern so that schedules are effective and efficient.
 
Some scheduling models include a fixed schedule method, which is used when the workload is predictable; a rotation schedule method, which ensures a balance between shifts; pattern schedule method, which sets the shift rotation by day of the week and is mainly applied where the workdays usually change cyclically from one schedule period to another; coverage schedule method, which is used where the pattern of the workload is not consistent, and a lot of flexibility is required; assignment schedule method that combines the aspect of time when one will be working and the assignment to be carried out; and team schedule method, where employees are scheduled as a group.
 
To review, see Scheduling IT Staff at a Bank: A Mathematical Programming Approach.
 

Unit 4 Vocabulary 

This vocabulary list includes the terms that you will need to know to successfully complete the final exam.

• assignment schedule method
• combination layout
• coverage schedule method
• earliest due date
• first-come, first-served
• fixed position layout
• fixed schedule method
• flow-shop
• identical processors
• job-shop
• longest processing time
• open-shop
• pattern schedule method
• preferred customer order
• process layout
• production scheduling
• product layout
• rotation schedule method
• schedule
• shortest processing time
• team schedule method
• uniform processors
• unrelated processors