Systematic Layout Planning
THE SYSTEMATIC LAYOUT PLANNING PATTERN
Systematic Layout Planning is an organized way to conduct layout planning, it consists of a framework of phases, a pattern of procedures, and a set of conventions for identifying, rating, and visualizing the elements and areas involved in a planning a layout.
We explained the framework of four phases in Chapter 1. In this chapter, the systematic layout planning pattern of procedures is described. The conventions will be introduced at the appropriate places in later chapters.
The strictly “layout planning” phases of any facilities rearrangement involve creating a general overall layout and subsequently a detailed layout plan for each portion of the general overall layout. In both Phase II and Phase III. In both Phase II and Phase III, the pattern to be followed is essentially the same.
Every layout rests on the three fundamentals:
- Relationships – the relative degree of closeness desired or required among things. Space – the amount, kind, and shape or configuration of the things being laid out. Adjustments – the arrangement of things into a Realistic is the best fir.
These three are always the heart of any layout planning project, regardless of products, processes, or size of the project. It is therefore logical and to be expected that the pattern of layout planning procedures is based directly on these fundamentals.
The SLP Pattern
In the previous chapter, we indicated the importance of Product (P) and Quantity (Q) to any layout. An analysis of them individually and in their “mix” is a necessary preliminary to any real layout planning. Process routing and equipment, supporting services, and timing information are also basic input data. And in addition, identifying the various activities (or areas) included in the layout is a preliminary planning step.
Box 1 of the pattern – and in-process – dominated industries often the most significant aspect of layout planning – is the flow of materials. By planning the layout around the sequence and intensity of material moves, we attain a progressive flow through the areas involved.
In addition to the operating or producing areas, many supporting – service areas must be integrated and planned. As a result, developing or charting the activity relationships – that is, the relationships among the service or support activities or functions is frequently or equal or greater importance then relationships based on the flow of materials alone.
These two investigations are then combined into Flow and / or Activity Relationship Diagram. Here the various activities, departments, or areas are geographically related to each other without regard to the actual space each requires.
Next, the space requirements: These are developed from analysis of the process machinery and equipment necessary and from the service facilities involved. Area requirements must, however, be balanced against the space available. Then the area allowed for each activity is “hung” on the activity relationship diagram to form a space relationship diagram.
The space relationship diagram is essentially a layout. But, in all likelihood, it is not an effective layout until it is adjusted and manipulated to integrate with its space any modifying considerations. These include such basic considerations as the handling method, operating practices, storage scheduling, and the like. As each potentially good consideration or idea concerning these features is thought up, it must be tested against practical limitations like cost, safety, and employee preference.
As the integrating and adjusting of the various modifying considerations and their limitations are worked out, one idea after another is probed and examined. The ideas that have practical value are retained and those that do not seem worthy, we end up with two, three, four, or five alternative layout proposals. Each of them will work; each has value. The problem lies in deciding which of these plans should be selected. These alternative plans may be termed Plan X, Plan Y, and Plan Z.
At this point, a cost analysis of some kind should be made for purposes of comparison and justification. in addition, some evaluation of intangible factors should also be made. This is called an evaluation of alternative layouts or an Evaluation of costs and Intangibles. As a result of this evaluation, one of the alternatives is chosen – although frequently a modification or combination of two or more layouts may actually result from the evaluation process itself.
The alternative layout that is chosen becomes the Selected Layout, the General Overall Layout. With the selection of this general overall layout, phase II is completed.
Tie-in P, Q, R, S, and T
We have seen how the pattern of Systematic Layout Planning is constructed. Now lets us relate it to the basic input data, P, Q, R, S AND T. P, Q, R, S, AND T underline most of the calculations needed for layout planning. The preparations of the data for the various boxes in the SLP pattern starts with these five basic elements. The product designs and sales forecasts must be woven together and integrated with a P-Q analysis- sometimes called volume-variety or study of product mix. The logical splits and combines various products or product groups or layout groupings are derived from the P-Q analysis. Specifically, this analysis of product mix, along with analyses of Routing(R), Services(S) and Times (T), leads us to identification or delineation of the individual activities (areas, machine groups, workplaces) involved, and thus often to the 4 actual types of layout.
P, Q, and R are then woven together to develop the flow of materials P, Q and S are woven together to develop a service activity relationship. From the flow of materials or the activity relationship chart or a combination of the two, the relationships are then diagrammed. It is Routing(R), together with Time(T), which essentially determines the machinery and equipment required. Similarly, the services (S) called for are translated into the various service facilities required. The process of machinery and equipment and the service facilities are then translated into space requirements. These space requirements are then worked into the SLP pattern as described above.
WHY LAYOUT PLANNING?
Many managers ask “Why plan layouts at all?” In some cases, it would seem to be about as easy to move the furnishings into an area and then have the fun of arranging them and rearranging them until you are satisfied. For the housewife who likes the freshness of rearranging her house occasionally, this makes sense. But for industry, merely rearranging will, in practically every case, result in lost time, idle equipment, and disruption of personnel. In addition, it may well lead to serious blunders in the use of a company‟s available land, in costly rearrangements, in actually tearing down buildings, walls or major structures which are still usable but which subsequently turn out to be roadblocks to efficiency and low-cost operation.
A little time spent in planning the arrangement before it is installed can prevent such losses. Moreover, it allows the integration of subsequent moves and rearrangements into a logical program. Planning makes facilities arrangements an orderly, logical sequence. Layout planning pays off: Obviously, it is much easier to move templates or replicas of facilities and equipment around on a piece of paper than it is to move the actual buildings, machinery, or equipment around. As professor School used to say, “You can make as many mistakes as you want in layout planning, and they will all pay for themselves if they avoid mistakes in the physical installation”.
Actually, from an installation standpoint, it is about as inexpensive to put in a good layout as to put in a poor one-frequently much less expensive. However, once a poor layout is installed, the cost of rearranging, disrupting production, and fighting your way through a new financial appropriation prohibit remaking it into a good layout.
The Key to Unlocking Layout Problems
There are two basic elements on which every layout problem rests:
- Product (or material to service) – what is to be made or produced.
- Quantity (or volume) – how much of each item is to be made.
Directly or indirectly, these two elements underline all other features or conditions in layout work. Therefore, facts, estimates, or information about these two elements are essential. By Product (or material or service) we mean the goods produced by the company or area in question, the starting materials (raw materials or purchased parts), the formed or treated parts, the finished goods, and / or service items supplied or processed.
Products may be termed, varieties, models, styles, part numbers, formulations, product groups, or material classes. By Quantity (or volume) we mean the number of goods or services produced, supplied, or used. Quantity may be termed number of pieces, tons, cubic volume, or value of the amount produced or sold. In terms of unlocking layout problems, these two elements represent the handle of any key we must grasp. For it seems obvious that if we are planning the layout of a Hotel or department, the layout must accomplish something. That “something” is certain products in certain quantities
After obtaining the product and quantity information, we must next learn about the routing (or process).
The routing refers to how the product or material will be made.
By routing, we mean the process, its equipment, its operations, and their sequence. Routing may be defined by operation and equipment lists, process sheets, flowsheets, and the like. The machinery and equipment used will depend on the operations selected to change the form or characteristics of the material. Similarly, the movement of work through the area to be laid out is dependent upon the sequence of the operations. Therefore, the operations involved in the process and their sequence become the body (or stem) of our key. Backing up the direct forming or assembly operations the producing activities or areas are a number of supporting services. In a sense, these are the things that give strength to the producing operations, for without adequate support, the producing equipment and workers could not function adequately.
By supporting services we man the utilities, auxiliaries, and related activities or functions that must be provided in the area to be laid out so that it will function effectively.
Supporting services include maintenance, machine repair, tool room, toilets, and locker rooms, cafeteria, first aid and shop, offices (or “out area”). It is common to include storage areas as a part of the supporting services as well.
Taken all together, the supporting services often occupy more floor area than the producing departments themselves. Therefore, adequate attention must be given to them.
One other basic element of the key to unlocking layout problems is time (or timing). By the time (or timing) we mean when, how long, how often, and how soon.
Time or timing involves when products will be produced or when the layout being planned will operate (one shift only, during festival season). Operating times for the producing operations determine how many of a given piece of machinery is required, which in turn determines the space required, manpower staffing, and operation balancing. Urgency (of delivery of action) is also a part of timing, as the frequency of lot or batch “run” and the response of supporting services.
Perhaps the most important of all, time affects us the layout planners. Every layout project takes a certain amount of time to accomplish, and usually, there is a deadline to meet.
Phases of layout planning
The four steps that the layout planner takes may be translated into what is known as the “Four Phases of Layout Planning”. These include the following:
Phase I – Location
Determine the location of the area to be laid out.
This is not necessarily a new site problem. More often it is one of determining whether the new layout (or re-layout) will be in the same place it is now, in a present storage area which can be made free for the purpose, in a newly acquired building or some other potentially available space.
Phase-II – General Overall Layout
Establish the general arrangement of the area to be laid out.
Here the basic flow patterns and the areas allocated are brought together in such a way that the general size, relationships, and configuration of each major area are roughly established. Phase-II is sometimes termed block layout or area allocation of the merely rough layout.
Phase-III – Detailed Layout Plans
Locate each specific piece of machinery and equipment.
In detail planning, the actual placement of each specific physical feature of the area to be laid out is established. And this includes utilities and services as well. The detailed layout plan is customarily a sheet or board with replicas of the individual machines or equipment placed or drawn thereon.
Phase-IV – Installation
Plan the installation, seek the approval of the plan, make the necessary physical moves.
Once the detailed layouts are completed (Phase III), considerable detailing of installation drawings and planning of moves must be worked out. Funds for the installation must be appropriated and the actual moves to install the machinery, equipment, and the services as planned must be made.
These four phases come in sequence, but, for best results, they should overlap each other. Every layout project passes through these four phases even though the layout planning analyst may not be specifically charged with the responsibility for Phase I and / or Phase IV. That is, he must make sure that Phase I has been agreed to or that a specific decision has been, or will be made as to where the layout he is planning is to be located. Obviously, he cannot be very specific about his detailed layout planning if he does not have information about the number of floors, ceiling heights, column spacing, and building features. All the generally dependent upon a location- or a reasonably acceptable assumption as to the location -having been established.
In many cases, the Phase I work actually involves a plant location study or a new site analysis. In such cases, the person actually responsible for making the layout plan may or may not be involved directly in Phase I.
Likewise, in Phase IV some other group may do the physical installation. However, in any case, the layout planning engineer should be aware of this four-phase sequence and should be prepared to integrate his work with Phase I and V.