Scheduling means specifying means, specifying the time that will be needed for the production of articles at each stage. Scheduling determines when an operation is to be performed or when work is to be completed; the difference lies in the detail of the scheduling procedure.
Definition of Scheduling
In the words of Kimball and Kimball,
Scheduling is the determination of the time that should be required to perform each operation and also the time necessary to perform the entire series, as routed, making allowance for all factors concerned.
That is to say, prior determination of when work is to be done is the function of scheduling.
Preparation of Schedules
Preparation of schedules (time tables for each and every operation) is not an easy task. In preparing the schedules, the planning department should consider various types of orders on hand and the expected dates by which they should be honored (i.e., promised to the customers). Orders may be general (regular) or urgent (rush). In the case of rush orders, overtime by the workers is needed.
Regular orders can be completed within a stipulated time. At times, it is also quite likely to receive the repair orders on the goods already sold. Goods sold should be repaired by the firm during the guarantee period of the goods.
Types of Schedules
As far as the scheduling is concerned, three types of schedules are required to be prepared:
1. Master Schedule
This indicates desired quantities of each type of product to be produced on a daily or weekly or monthly or quarterly basis to meet the customers’ orders or forecasted demand.
2. Operation schedule
It refers to fixing the final total time required to do a particular piece of work (operation)
3. Daily Operation Schedule
It reveals the time required to do each detailed operation of a given job with the assigned machine or process.
Objectives of Scheduling
1. Meeting customer and finished goods inventory delivery requirements.
2. To achieve the required rate of output with a minimum of delay and disruption in processing.
3. To have maximum utilization of men, machine and materials by maintaining a smooth flow of materials along the production line.
4. To prevent unbalanced use of time among departments and work centres with a view to eliminate idling of men and machines.
5. To complete the production at minimum total cost and to reduce the manufacturing cycle time to the minimum.
6. To deliver products in time as per the delivery schedule committed to the customers.
Problems in Scheduling
Scheduling cannot be done perfectly due to the following problems:
1. Lack of correct and up to date information concerning lead time, production time, lot size.
2. Resources constraints, capacity shortages, delay in supply of materials, machine break downs etc.
3. Absenteeism, lack of skill and experience in labour and labour inefficiency resulting in actual time taken to complete a job exceeding the allowed time (i.e., standard time).