Subject: Production Engineering and Robotics

Difficulty: Medium

Marks: 8 Marks

Schedules are of Two Types

[1] Master schedule

[2] Shop or production schedule

[1] Master Schedule:

• Scheduling usually begins with the master schedule.
• It represents the master plan of manufacturing in a given period of time.
• Master schedule to stock begins with a sales forecast.
• Function of master schedule is to minimize the difference between regular sales and steady production.
• Nature of master schedule depends upon whether the product is produced according to order or to stock.
• Master Production Scheduling (MPS), otherwise known as an over-all schedule, focuses on a planning horizon, divided into equal time periods (time buckets, such as by month).
• It includes a plan for the production of individual commodities such as staffing, inventory, etc for the allotted time period.
• A MPS usually dictates when and how much of each product is going to be produced, based on criteria such as demand, capacity, and inventory availability.
• MPS aids in decision making by generating a set of output data based on forecast demand, production costs, inventory money, customer needs, production lead time, and capacity.
• The resulting output information includes the amounts to produce, staffing requirements, quantity of product available to promise, and projected available funds for production. It also sets the expectations of the revenue that the business is likely to generate.

[2] Shop or Production schedule :

• Total number of products to be manufactured. Number of assemblies or sub-assemblies requires. Manpower and machine requirements are decided during this scheduling.

• This type of scheduling may be done for a month or quarter or yearly.

  [a] Long-term Scheduling Long term scheduling is performed when a new process is created. The long-term scheduler limits the number of processes to allow for processing by taking the decision to add one or more new jobs, based on FCFS (First-Come, first-serve) basis or priority or execution time or Input/Output requirements. Long-term scheduler executes relatively infrequently.

  [b] Medium-term Scheduling Medium-term scheduling is a part of the swapping function. This scheduler works in close conjunction with the long-term scheduler. It will perform the swapping-in function among the swapped-out processes. Medium-term scheduler executes some what more frequently.

  [c] Short-term Scheduling Short-term scheduler is also called as dispatcher. Short-term scheduler is involved whenever an event occurs, that may lead to the interruption of the current running process. Short-term scheduler executes most frequently.