Construction, Costs Associated, and Techniques of Plant Layout…
Construction of Plant Building:
For effective and efficient operation of the plant, the design of the building is one of the main considerations. The building housing the plant should be designed in such a way that it can meet the requirements of the concern’s operations and its layout.
According to James Lundy,
“An ideal plant building is one which is built to house the most efficient layout that can be provided for the process involved, yet which is architecturally ultra active and of such a standard shape and design as most flexible in its use and expensive units construction.”
The layout may be said to be efficient if it is housed in a building that ensures comfort and health of workers engaged in the plant concerning heat, light, humidity, circulation of air, etc. and on the other hand, it protects the plant and equipment and materials from the weather.
There are several factors which are to be considered in constructing a new building for housing the plant. These are:
Adaptability:
The building structure should be adaptable fully to the needs and requirements of the plant. In the beginning, most of the enterprises carry their business in a rented building which is generally not suitable to the needs and special requirements of the industries with the obvious reason that landlord constructs the building to suit average conditions of a manufacturing unit and they cannot be persuaded to make the necessary changes affecting the flexibility. As to the degree of adaptability, it may be needed that buildings are more easily adapted to fit the needs of the continuous process than to those of any other.
Provision for additions and extensions:
In designing and constructing a new factory building, care must be taken to provide for additions and extensions which may arise to meet the necessary and peculiar needs in due course of time. There must be every possibility to add new units without disturbing the existing manufacturing system. Kimball and Kimball have rightly suggested that “an ideal building plan is one built on some (unit) system like a sectional bookcase so that additional units can be added at any time without disturbing the manufacturing system and organization”. As a general rule extension can be made most conveniently at right angles to the direction of flow of work.
The number of stories:
Another important decision while designing new plant building is to consider the number of stories to be built, Le., whether the building should be single-stories or multi-stories. The choice between single and multi-stories depends obviously on various factors such as the nature of the product, proposed layout, the value of land, the cost of construction. Before deciding the number of stories, the management should bear in mind the comparative advantages and disadvantages of one story and many stories.
Costs Associated With Plant Layout:
The costs associated with a decision on plant layout are;
- Cost of movement of materials from one work area to another.
- The cost of space.
- Cost of a production delay, if any, which are indirect costs.
- Cost of spoilage of materials, if any, when the materials are stacked or stored in conditions which deteriorate the quality of the material.
- The cost of labor dissatisfaction and health risks.
- Cost of changes required, if the operational conditions change in the future. This is a long-term cost.
A good layout should minimize all these costs put together.
Techniques of Plant Layout:
In designing or improving the plan of plant layout, certain techniques or tools are developed and are in common use today.
The techniques or tools are as follows;
Charts and Diagrams:
To achieve work simplification, production engineers make use of several charts and diagrams for summarising and analyzing production process and procedures.
These include;
- Operation Process chart: It subdivides the process into its separate operations and inspections. When a variety of parts and products are manufactured which follow different parts across several floor areas, an operation process chart may be necessary for the important material items or products. The flow lines on the chart indicate the sequence of all operations in the manufacturing cycle.
- Flow process chart: This chart is a graphic summary of all the activities taking place on the production floor of an existing plant. By preparing this type of chart, it can be found out as to where operations can be eliminated, rearranged, combined, simplified or sub-divided for greater economy. This chart will also identity inflexible processes which cannot be adapted to the output of redesigned models or related outputs.
- Process flow diagram: The diagram is both a supplement and substitute of process flow chart. It helps in tracking the movement of material on a floor plan or layout drawing. A diagram may be drawn to scale on the original floor plan to show the movement of work. It is a good technique to show long material hauls and backtracking of present layouts, thereby indicating how the present layout may be improved. The flow of several standard products can be shown by colored lines.
This diagram can be used to analyze the effectiveness of the arrangement of plant activities, the location of specific machines, and the allocation of space. It shows how a more logical arrangement and economical flow of work can be devised.
Machine data card:
This card provides full information necessary for the placement and layout of equipment. The cards are prepared separately for each machine. The information generally given on these cards include facts about the machine such as the capacity of the machine, space occupied, power requirements, handling devices required and dimensions.
Templates:
The template is the drawing of a machine or tool cut out from the sheet of paper. The area occupied by a machine is shown by cutting to scale. The plant layout engineer prepares a floor plan based on relevant information made available to him.
Templates representing machines, tools, conveyors, furnaces, ovens, inspection stations, tanks, storages, bins, trucks etc. are then laid out on the floor plan according to the sequence or groupings indicated on the operation process chart and the overall layout plan prepared by the engineers and helps in trying out at possible alternative arrangements.
The template technique is important because;
- It eliminates unnecessary handlings.
- Minimized backtracking of materials.
- It makes the mechanical handling possible.
- They provide a visual picture of the proposed or existing plan of the layout at one place, and.
- They offer flexibility to meet future changes in production requirements.
Scale models:
Though two-dimensional templates are now in extensive use in the field of layout engineering it is not of much use to executives who cannot understand and manipulate them. One important drawback of the template technique is that it leaves the volume, depth, height, and clearances of machines to the imagination of the reader of the drawing.
These drawbacks of template technique have been removed through the development of miniature scale models of machinery and equipment cast in metal. With scale models, it has now become possible to move tiny figures of men and machines around in miniature factors. The miniature machines and models of material handling equipment are placed in a miniature plant and moved about like pawn on a chessboard.
Layout drawings:
Completed layouts are generally represented by drawings of the plant showing walls columns, stairways, machines and other equipment, storage areas and office areas.
The above techniques and tools are used for the planning of layout for the new plant.
