Plant layout and design is an important component of a businesses overall operations, both in terms of maximizing the effectiveness of the production process and meeting the needs of employees. Plant layout refers to the arrangement of physical facilities such as machinery, equipment, furniture etc. within the factory building in such a manner so as to have quickest flow of material at the lowest cost and with the least amount of handling in processing the product from the receipt of material to the shipment of the finished product. It may be defined as a technique of locating machines, processes and plant services within the factory so as to achieve the right quantity and quality of output at the lowest possible cost of manufacturing. It involves a judicious arrangement of production facilities so that workflow is direct. The basic objective of layout is to ensure a smooth flow of work, material, and information through a system.
Plant layout is an important decision as it represents long-term commitment. An ideal plant layout should provide the optimum relationship among output, floor area and manufacturing process. It facilitates the production process, minimizes material handling, time and cost, and allows flexibility of operations, easy production flow, makes economic use of the building, promotes effective utilization of manpower, and provides for employee’s convenience, safety, comfort at work, maximum exposure to natural light and ventilation. It is also important because it affects the flow of material and processes, labor efficiency, supervision and control, use of space and expansion possibilities etc.
The most important features of an ideal plant layout are;
- Transport: Movement of materials is a waste. Minimize the amount of movement by arranging processes in close proximity to each other. Factory layouts can often be the fundamental cause of excess transportation. When appropriate, re-laying out the machines within a factory from a functional to a cellular layout has been found by many companies to help not just reduce transportation waste but also reduce work-in-progress (WIP) and waiting. Items being moved unnecessarily incur a cost.
- Inventory: Many companies produce above what is required to fulfill the order, this may be due to quality problems along the production process or the often mistaken belief that is saves money by manufacturing larger quantities. Too little inventory can lose sales; too much inventory can hide problems.
- Motion: Generally, this waste applies to production personnel having to move out of their work area to locate tools, materials, etc. Remove unnecessary motion of the operations and improve the ergonomics of the workplace. People moving unnecessarily also incur a cost.
- Waiting: Minimize waiting time (operators waiting for machines or products waiting around in factories either as finished goods or work in progress). Aim for a smooth flow.
- Overproduction: Always aim to make exactly what the customer orders, just in time, to the correct quality standard. On the shop floor, this generally occurs because changeover times are high, equipment is unreliable, the process is unreliable (causes defects), and standard cost accounting metrics are used. However, probably the biggest reason for overproduction is poor information flow (communication) between facilities.
- Over Processing: Use machines which are of an appropriate capacity and capable of achieving the required quality standard. This usually refers to using larger scale equipment than necessary; it also refers to building in rework to a process. It can also refer to using the wrong suppliers and/or the wrong process.
- Defects: Reducing the number of defects directly reduces the amount of waste. Aim for zero defects.
The efficiency of production depends on how well the various machines; production facilities and employee’s amenities are located in a plant. Only the properly laid out plant can ensure the smooth and rapid movement of material, from the raw material stage to the end product stage. Plant layout encompasses new layout as well as improvement in the existing layout.