Plant layout is a plan of the most effective arrangement of the physical facilities and manpower for the manufacture of the product. Plant layout encompasses much more than the mere planning of the arrangement of the production equipment and should include a careful study of the following: 1. External transportation facilities. 2. Receiving operations (unloading, inspection, stores) 3. Production activities. 4. Service & auxiliary operations. 5. Quality control and inspection areas. 6. Packing operations. 7. Storage operations. 8. Shipping operations.
Plant layout covers the planning of space requirements for all activities in an industrial firm – offices, warehouses, rest rooms and all other facilities Objectives of Plant Layout. The primary goal of plant layout is to maximize profits by the arrangement of all plant facilities to the best advantages of the Total Manufacturing Equation – men, materials, machines and money. If a finished layout is to fulfill this goal, is should be planned with the following objectives in mind. 1. Facilitate the manufacturing process. 2. Minimize materials handling. 3.
Maintain flexibility of arrangements and of operation. 4. Maintain high turnover of work in progress 5. Hold down investment in equipment 6. Make economical use of floor area. 7 Promote effective utilization of manpower. 8 Provide for employee convenience, safety and comfort in doing the work. All these objectives can be summarized as the planning of the plant for the optimum relationship between output, space and manufacturing cost. Factors affecting Plant Layout 1. Product. 2. Volume or rate of production. 3. Quality. 4. Equipment. 5. Type of manufacture 6. Building 7. Plant site 8. Personnel . Materials handling plan. Muther has given a key to lay out. P – look at the products to be manufactured today and tomorrow Q – Examine the quantity that has to be manufactured …. more products less quantity or vice versa – This is normally important for jobbing industry. R – Routing of the sequence of operations that take place. S – Service and supporting services required. T – Timing estimates of the operations done on the job Basic Plans for Plant Layout. There are basically two main ways in which a plant may be laid out. They are process layout and product layout. Process Layout:
In process layout, the type and operational characteristics of the manufacturing equipment are the determining factors in the arrangement of the factory. This basic plan can be readily identified ,as such plants will have machine departments, clearing departments, finishing rooms and assembly floors. Even within such departments machines of similar work characteristics are commonly grouped together (Lathes, milling machines, drill presses and so on) Product Layout In product layout the work to be performed on the produce is the determining factor in positioning of manufacturing equipment.
The aim is to arrange machines in the order of operations that are performed on the many component parts, on sub assemblies, and on the final assembly of the item being manufactured. Thus each work station – either machine of work bench – does whatever operations on the product that follows the work done at the proceeding work station, then passes the product to the next work station in the line where the next operation is performed Relative advantages of Product and Process Layout. Product Layout Process Layout 1.
Lower total materials handling cost. 2. Lower total production time. 3. Less work in progress 4. Greater incentives for groups of workers to raise level of performance and greater possibility for group incentive plans with broader coverage. 5. Less floor area required per unit of production. 6. Greater simplicity of production control – fewer controls & records needed, lower accounting costs. | 1. Less duplication of equipment. Hence lower total investment in equipment. 2. Greater flexibility of production. 3. Better and more efficient supervision possible through specialization. . Greater incentive for individual workers to raise level of performance and greater possibility for individual incentive pay plan. 5. Better control of complicated or precision processes, especially where much inspection is required. 6. Easier to handle breakdowns of equipment by transferring work to other machine or station. | WHEN TO USE PRODUCT OF PROCESS LAYOUT Product Layout 1. One or few standard products. 2. Large productions of each item over a considerable period of time. 3. Possibility of time and motion studies to determine rate of work. . Possibility of good labour & equipment balance (each work station producing equivalent number of units per hour) 5. Minimum of inspection required during sequence of operations. 6. Minimum of very heavy equipment requiring special facilities (isolation from general production areas. 7. Materials and products permit bulk or continuous handling by mechanical means. 8. Little or no occasion to use the same machine or work station for more than one operation (minimum number of set ups required. | Process Layout 1.
Many types or styles of products or emphasis on special orders. 2. Relative low volume of production on individual items (overall production may be high). 3. Adequate time and motion studies difficult to make. 4. Difficult to achieve good labour and equipment balance. 5. Many inspections required during a sequence of operation. 6. High proportion of very heavy equipment requiring special treatment. 7. Materials or products to large or heavy to permit bulk or continuous by mechanical means. 8. Frequent necessity to use some machine or workstation for two or more different operations. |
In addition to process and product layout, there is a layout by fixed position or by fixed material location. This is a layout where the material or major component remains in a fixed place. This reduces handling of the major assembly unit, allows highly skilled operations to complete their work at one location, and permits frequent changes in product design and also in sequence of operations. This layout plan is suitable for a variety of products and intermediate demands and is more flexible in that it does not require highly organized or expensive layout engineering production planning or safeguard against break in work continuity.
The disadvantages of the system is that, as all tools and other materials are to be moved to one place, the movement of materials and machines becomes costly and cumbersome. Principles of plant layout: 1. Principle of overall integration: That layout is best which integrates men, materials, machinery, supporting activities and any other consideration in a way that results in the best compromise. 2. Principle of minimum distance moved: Other things being equal, that layout is best that permits the material to move the minimum distance between operations.
Every job requires some movement and material movement cannot be eliminated. Efforts to concentrate on specific machines on each operation and specific man on a job is the essence of efficient production. Handling does not add to the value of the product and hence movement cost should be minimized. 3. Principle of flow: Other things being equal that layout is best which arranges the work area for each operation or process in the same order or sequence that forms, treats or assembles the material. This means that there should be no backtracking or cross movement and material should guide through the plant without interruption.
Flow does not imply movement in a straight line, neither does it limit the motion to one direction; many excellent layouts call for zigzag or circular flow of materials. 4. Principle of cubic space: Economy is obtained by using effectively all available space – both vertical and horizontal. Fundamentally, layout is the arrangement of space, that is the arrangement of various spaces occupied by men, materials, machinery and supporting activities. They are all 3 dimensional and so good layout should occupy cubic space of the plant as well as floor area.
Besides the 3M’s can move in any of the three directions. 5. Principle of satisfaction and safety: Other things being equal, that layout is best which makes work satisfying and safe for workers. Workers satisfaction is important and since men are to work in the layout their safety comfort and morale are important to achieve savings in operating costs. 6. Principle of flexibility: Other things being equal, that layout is best which can be adjusted and rearranged at minimum cost and inconvenience. To summarize, it is essential that the plant layout Moves materials minimum distances * Avoids or minimizes the backtracking of materials * Plans for a minimum of materials handling * Uses manufacturing space economically * Permits flexibility and possible expansion. Plant Layout Procedure In brief, the procedure to be followed in designing a plant layout is as follows: 1. Accumulate all basic data that will be needed (PQRST) 2. Analyze and coordinate this basic data (AEIOUX) 3. Determine the general floor pattern for the materials in the process. 4. Design the individual workstations or production centers. . Assemble the individual layouts into the total layout in accordance with the general floor pattern and the building facilities. (The existing peripheral wall and load-bearing columns remain constant) 6. Coordinate this plan with the plan for the handling of materials (Preferably heavy machinery on lower floors and lighter machinery upstairs) 7. Complete the plant layout. 8. Prepare a request indicating funds needed and justify the expenditure of the funds. 9. Convert the plant layout into floor plan for erection and location by the civil department.