Page 108 - DMGT501_OPERATIONS_MANAGEMENT

Operations Management

Notes In the table, the first column represents a product or a group of products. The second column
represents the volume the product or the product group constitutes of the total flow in the
layout. The third column shows the sequence of departments through which the product passes.
For example, Product 'I' will go to the lathe department, from there it will go to shaping, then
drilling, milling, grinding and finally to the Inspection Department before the product is stocked
(refer Figure 4.3). The second column represents the percentage volume of the product group.
The total percentage volume of all the product groups will always be less than or equal to 100
per cent. In the example, it is less than 100 per cent. In order to simplify the problem, similar to
ABC analysis of inventory systems, products that do not have significant effect on the total
production pattern, have not been shown in Table 4.1. However, care must be taken to ensure all
significant products and product groups are included.

Figure 4.3: Schematic Representation of Material Flow

The input-output information on all the departments is computed and reflected in a schematic
diagram. This is called the Material Flow Diagram. The schematic material flow diagram for our
example is shown as Figure 4.4. The steps involved in creating the material flow diagram in the
Spiral Method are:
1. Draw a circle to represent each department or activity area.
2. On the left side of the circle draw a line to represent incoming material from each activity,
which immediately precedes the activity of interest for any product group.
3. On each line to the circle indicate the quantity or per cent of total activity between the two
sequence steps.

4. At the right of the circle draw a connecting line that denotes where the material has to go
when the operation has been completed.
5. These lines tell us the quantity or percentage of total activity represented by the completed
material.
These five steps give schematic representation of various departments and their material inflow
and outflow. Remember, totals have to tally. For example, take the store figures. The total that
leaves the store has to equal 91.5, the figure given in Table 4.1. Similarly, the total reaching
'stock' will also be 91.5. You also have to ensure that inputs and outs are balanced for each
activity or department.

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