Routing

Routing may be defined as the selection of path which each part of the product will follow while being transformed from raw materials to finished products. Path of the product will also give sequence of operation to be adopted while being manufactured. In other way, routing means determination of most advantageous path to be followed from department to department and machine to machine till raw material gets its final shape, which involves the following steps:

• Type of work to be done on product or its parts.
• Operation required to do the work.
• Sequence of operation required.
• Where the work will be done.
• A proper classification about the personnel required and the machine for doing the work.

The main objective of routing is to determine the best and cheapest sequence of operations to be followed. In case of continuous manufacturing units where standardized products are produced routing becomes automatic. In case of job order and batch production every product requires different design and varying sequence of operations, another object of routing is to help in determining proper tools and equipment’s and the number of workers required for carrying out the work.

For effective production control of a well-managed industry with standard conditions, the routing plays an important role, i.e., to have the best results obtained from available plant capacity. Thus routing provides the basis for scheduling, dispatching and follow-up.

The various routing techniques are listed below.

Route card

This card always accompanies with the job throughout all operations. This indicates the material used during manufacturing and their progress from one operation to another. In addition to this the details of scrap and good work produced are also recorded.

Work sheet

It contains

• Specifications to be followed while manufacturing.
• Instructions regarding routing of every part with identification number of machines and work place of operation.

This sheet is made for manufacturing as well as for maintenance.

Route sheet

It deals with specific production order. Generally made from operation sheets. One sheet is required for each part or component of the order. These includes

• Number and other identification of order.
• Symbol and identification of part.
• Number of pieces to be made.
• Number of pieces in each lot—if put through in lots.
• Operation data which includes:
• List of operation on the part.
• Department in which operations are to be performed.
• Machine to be used for each operation.
• Fixed sequence of operation, if any.
• Rate at which job must be completed, determined from the operation sheet.

Move order

Though this is document needed for production control, it is never used for routing system. Move order is prepared for each operation as per operation sheet. On this the quantity passed forward, scrapped and to be rectified are recorded. It is returned to planning office when the operation is completed.

Procedure

The following steps are taken for a routing procedure:

Deciding what Part to be made or Purchased: The product is thoroughly analyzed to find out which parts are required for it. The second decision is taken regarding the production or purchase of various components. Some components may be manufactured by the firm and others may be procured from the market. During slack periods most of the components may be manufactured by the firm but when industrial activity is at its peak then supplies from outside may be contracted.

These decisions are taken after considering factors such as:

• The relative cost involved;
• Purchase policies of the firm;
• Technical considerations; and
• Availability of equipment and personnel.

Determining Materials Required: The analysis of the product will enable us to know the type of materials required for producing various components. The right type of quality, quantity, and time when needed should also be decided in advance.

Determining Manufacturing Operations and Sequences: The manufacturing operations and their sequences can be determined from technical experience and layout of machines. A sound and economical operation is selected for manufacturing various components.

Determining of Lot Sizes: A decision has to be taken about the number of units to be produced in one lot. If production is carried on the basis of orders then size of the lot depends upon the quantity ordered plus some units for possible rejections during the process. When production is done for the stock then lot is decided by considering various economies which may accrue.

Determining of Scrap Factors: There may be some scrap during the course of manufacture. The finished products are generally less than the units introduced at the beginning. The scrap during manufacturing should be anticipated so that routing is facilitated. If products pass through three processes and a normal scrap is 5% of input at every stage then it will be easy to anticipate the units entering various processes and arrange equipments and manpower.

Analysis of Cost of the Product: The determination of cost of products may be the duty of cost department but still production department makes records of direct materials, labour, direct and indirect expenses. These estimates are greatly useful to costing department also.

Preparation of Production Control Forms: The carrying out of routing will be facilitated if forms are prepared to collect information for control purpose. The requirements are: job cards, inspection cards, move tickets, labour cards, tool tickets, etc.