Plot Plan
It is a diagrammatic representation of the building outline, showing its location on the property, the location of external transportation facilities and other items such as tanks, storage areas, parking lots etc. It can be used as a key or master drawing for locating separate detailed drawings of the layout. The plot plan is presented in the form of a drawing or as a scaled model.
Block Plan
A block plan is a diagrammatic representation showing internal partitions of departments (Figure II), columns and area allocation but not machinery, equipment and facilities. This is usually presented in the form of drawings and is used as a reference or master for detailed layouts of different departments. This shows the area allocations for aisles, column spacing etc.
Detailed Layout
It is a diagrammatic representation of the arrangement of equipment operator and materials along with the arrangement of supporting activities. The detailed layout can be constructed by. utilizing any one of the following methods
- drafting or sketching
- Templates
- Models
A template is a scaled representation of a physical object in a layout may be of a machine, workman, material handling equipment, work-in-process storage etc.
Models are three dimensional representations of the physical objects which give depth to the layout and make it more presentable.
These templates and models may be prepared from cardboard, paper, sheet metal, plastic or wood and may be black and white or coloured. These may be attached to the backing material by using various fastening devices such as glue, staples, rubber cement, thumbtacks, magnetism etc.
Checking the Layout
The layout finally developed should be checked for
- Overall integration
- Minimum distance moved
- Smooth flow of the product
- Space utilization
- Employee satisfaction and safety
- Flexibility
The flexibility should be introduced in building and services and in equipment by mounting them on wheels or skids.
Evaluation of Layout
The evaluation may be done of an existing layout or of an alternative layout. The basis for evaluating the layout might include:
- The objectives of layout planning
- Cost comparison with other alternatives
- Return on investment
- Intangible factors which must be evaluated on the basis of judgment.
- Productivity evaluation
- Space evaluation
- ranking
- Pilot plant
- Sequence demand-straight line-considering the sequence of operations on a variety of parts
- Factors analysis by weighing various factors according to their importance
The optimizing evaluation can also be done by using Operation Research Techniques such as
- Linear Programming
- Line Balancing
- Level Curve Concept
Mathematical models express the effectiveness of layout as a function of a set of variables which can be evaluated. Some other mathematical techniques of evaluation are:
- Monte Carlo Method
- Queuing Theory
- Engineering Economy
- Analogues
These are not discussed in details here. Installation of Layout
The layout is presented in the following ways:
- The Visual presentation of the layout itself, supplementary details and facts and supplementary charts and displays
- An Oral report
- A Written report
When the final layout is approved it is installed in a number of phase, and it is needed to prepare
- Detailed drawings
- Precise specifications of production and materials handling equipment
- Detailed listing of all equipment and utility requirements
- Actual plans and schedule of construction and installation
The techniques of project management such as CPM/PERT may be used for planning and monitoring the progress of the layout installation.