Mumbai University > Mechanical Engineering > Sem 7 > Production planning and control

Marks: 5M

Year: May 2016

The factors that affect scheduling are grouped into two categories viz;

Internal factors: Affect an entity (e.g. a company) from within. External factors: Influence an entity (e.g. an organisation) from outside.

Factors affecting scheduling internally are:

1. Stock of finished goods kept by company.
2. Process intervals of each product.
3. Type of machines available.
4. Availability of personnel.
5. Availability of materials.
6. Manufacturing facilities available in the company.
7. Economic production runs (EPR) or optimum lot size.
8. Factors that affect scheduling externally are:
9. Consumer demand.
10. Consumer delivery dates.
11. Inventories (stock of goods) with dealers and retailers.

Now let's discuss internal and external factors influencing scheduling.

Internal Factors Affecting Scheduling

1. Finished goods inventories: Scheduling depends on how much stock of finished goods is kept by the company. Most companies keep, one month's supply of each product, as stock. If the company's product is fast moving or slow moving, then scheduling will have to be changed.
2. Process intervals: It depends on the process intervals of each product. Process interval is the time required to produce a product. Different products have different process intervals. For example, the process interval of a car is more than that of a soap. Scheduling will be different for each process interval.
3. Type of machines available : It also affected by the type of machines available. If the company has old and outdated machines, the schedule must keep provisions for the breakdown of machines. Modern and computerized machines makes scheduling very easy.
4. Availability of personnel : Scheduling also depends on the availability of personnel. If the company has untrained and inexperienced employees, then they will take more time to produce a product. So, the schedule must keep provisions for this. A faster schedule will be required for trained and experienced employees.
5. Availability of materials : It is also affected by the availability of materials. If a regular supply of materials is available, then the company can do normal-scheduling. However, if the supply of materials is irregular, the schedule must be made flexible. That is, when the supply is good then the schedule will be fast and vice versa.
6. Manufacturing facilities : Scheduling depends on the manufacturing facilities available in the company. This includes space for new machines, employees, etc. It also includes the availability and supply of electricity and water, which may be required for production. If all the required infrastructure is available, then the production schedule can be fast and vice versa.
7. Economic production run (EPR) : It also depends on the economic production runs. Economic production runs (EPR) means the optimum lot size. That is, how many items must be produced in one lot in order to minimize the cost of production. If the company produces more or less than the optimum lot size, then the cost of production will increase. There are many formulas for calculating optimum lot size. Scheduling must be done only after calculating the optimum lot size.

External Factors Affecting Scheduling

The external factors affecting scheduling are as follows:

1. Consumer demand : Scheduling also depends on the consumer demand. Consumer demand can be found out by sales forecast. So, the production schedule is prepared according to the sales forecast. However, it has to be adjusted (changed) when the actual demand is different from the sales forecast.
2. Consumer delivery dates : The production schedule also depends on the consumer delivery dates. The consumer is the most important person in a business. So, this factor must be given more importance than other factors. The production schedule must be made in such a way that it will guarantee timely delivery to the consumers. In case of seasonal goods, production must be spread out throughout the year; so, there will not be too much pressure in demand season.
3. Dealers and retailers inventories : It also depends on the stock of goods (inventories) with dealers and retailers. The production manager must find out how much stocks is held by dealers and retailers. He must also know why they are keeping this stock. Are they keeping this stock to meet current demand? If yes, then normal-scheduling can be done. However, if they are keeping stock in anticipation of future demand, the scheduling will have to be slowed down because there will be fewer orders in the future.