Page 221 - DMGT206_PRODUCTION_AND_OPERATIONS_MANAGEMENT

Production and Operations Management

Notes captures costs to identify a location that minimizes the total weighted loads moving into and
out of the facility.
Another popular technique similar to the Load Distance Model for plant layout is the Travel
Chart Technique. In this, we start from an initial layout, which may be the existing layout. The
designer concentrates only on the critical points of the layout. Critical points are generally the
areas, which have high volume-distance movement of materials. The designer attempts to
modify the layout so that there is maximum improvement in the critical points.

11.3.2 Optimisation in Process Layouts

Spiral Analysis-Use of Schematic Diagram to Solve Layout Problem
In certain types of layout problems, numerical flow of items between departments is either
impractical to obtain or does not reveal the qualitative factors that may be crucial to the placement
decision. In these situations, a semi quantitative technique like the Spiral Analysis can be used.
Spiral Analysis involves:
1. Developing a relationship chart showing the degree of importance of having each
department located adjacent to every other department.
2. From this chart, an activity relationship diagram, similar to the flow graph is obtained,
and is used for illustrating material handling between departments.
The objective of the spiral analysis is to arrange the departments in such a manner that the
transportation costs of material handling are minimized. The analysis tries to find an option
that provides the most direct flow of material between different departments.
Anand Parvat Industries plans to redesign the layout of its factory. The factory produces five
major products. The initial layout plan is shown in Figure 11.4. In addition to incoming and
outgoing stores, the factory has 6 departments. This data with the flow paths and volume for the
different products is captured in Table 11.1.
Table 11.1: Sequence of Processing Departments

Product group Percentage volume Flow path through departments
I. 18.2 Stores, A,B,C,D,E,F, Stock
II. 10.9 Stores, B,D,E,F, Stock
III. 29.3 Stores, A,B,D,C,F, Stock
IV. 24.2 Stores, B,C,D,C,E,F, Stock
V. 8.9 Stores, B,C,D,F, Stock
Total 91.5

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.

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 11.4). 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

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