production planning and control

Planning the production in advance comes under production, planning and control. Setting the exact route of each item and fixing the starting and finishing date for each item is the key operation. Giving the production orders to different shops and observing the progress of products according to order.

Systematic view of the various functions of the PPC departments are written as follows:

Main objectives of Production Planning & Control

• Establishing the sequence of operations to continue production.
• To issue a coordinated work schedule of production to the supervisor/foreman of various shops.
• To plan out the plant capacity to provide sufficient facilities for future production programs.
• To maintain sufficient raw materials for continuous production.
• following up production schedule for ensuring delivery promises.
• To determine the performance of different shops and individuals.
• giving authority to the right person for doing the right job.

Related departments with PPC

Aggregate Planning(AP)

Aggregate planning is the planning for an intermediate range of time.

• The aggregate planning concentrates on scheduling production, personnel and inventory levels during intermediate-term planning the horizon such as 3-12 months.
• Aggregate plans play the role of an interface between strategic decisions (which fixes the operating environment) and short term scheduling and control decisions regarding the firm’s day-to-day operations.
• Aggregate planning focuses on manipulating several aspects of operations-aggregate production, inventory and personnel levels to reduce costs over some planning horizon and at the same time satisfying demand and policy requirements.

Planning hierarchy

Aggregate planning is classified in two types i.e.

• Aggregate Production Planning indicates the level of output,
• Aggregate Capacity Planning keeps capacity utilization at the desired level and tests the feasibility of planned output.

Types of Production Systems

• A transformation system in which a saleable product or service is created by working upon a set of inputs is known as a production system. Generally the inputs are in the form of men, machine, money, materials etc. They are broadly classified into three categories:
  
  • Job shop production
  • Batch production
  • Mass production

Classification of production systems are done based on the following types:

• Type of product
• Type of production line
• Rate of production
• Equipment used 

Job Production
In Job production, products are made to satisfy a particular order. However, that order may be produced-only once

• or at irregular time intervals as and when
• at irregular time intervals when a new order arrives or
• at regular time intervals to meet a continuous demand

The following are some of the important characteristics of job shop type production system:

• Machines and methods employed should be general-purpose as product changes are
  quite frequent.
• Planning and control system are flexible enough to handle the frequent changes in
  product requirements.
• Manpower should be skilled enough to deal with changing work conditions.
• In the process, inventory will usually be high as accurate plans and schedules do not exist.
• Product cost is usually high due to high material and labour costs.
• Machines are grouped on a functional basis (i.e. as lathe section, milling section etc.)
• Flexibility of this system is very high as management has to manufacture varying product types.
• To meet changing product requirements, material handling systems are also made flexible.

Batch Production
The manufacturing of a number of identical articles either to meet a specific order or to meet a continuous demand is called batch production. Batch can be manufactured either-

• only once or
• again and again at irregular time intervals as and when the demand arises or
• again and again at regular time intervals to meet a continuous demand

The following are some of the important characteristics of a batch type production system:

• As final product is somewhat standard and manufactured in batches, the economy of scale can be availed to some extent.
• Grouping of machines is done on a functional basis similar to the job shop manufacturing.
• Semi-automatic, special-purpose automatic machines are usually used to take benefit of the similarity among the products.
• Labor should have high skills as they might be required to work upon different product batches.
• Inventory is usually high in this process because of the type of layout and material handling policies adopted.
• Generally, production planning and control is tough because of the odd size and non-repetitive nature of the order.

Mass Production

To meet the continuous demand of the product, the same type of product is manufactured in mass production. Usually, the demand of the product is very high and the market is going to sustain the same demand for a sufficiently long time.
The following are some of the important characteristics of a mass production system:

• As a same product is manufactured for sufficiently long time, machines can be laid down in order of processing sequence. For mass production system, product type layout is most appropriate.
• For part manufacturing, standard methods and machines are used.
• Most of the equipment are semi-automatic or automatic in nature.
• Material handling is also automatic (such as conveyors).
• As most of the facilities are automatic, semi skilled workers are usually hired.
• Planning and control of the system is much easier as product flows along a pre defined line.
• Because of the high rate of production, cost of production is low.
• In process inventories are small since the production scheduling is not complicated and can be implemented with ease.