FACILITY LAYOUT PROBLEM Mohamed Iqbal Pallipurath

FACILITY LAYOUT PROBLEM Once a firm has decided where a facility will be located, the next important decision is the Arrangement of people and Equipment within the facility.

FACILITY LAYOUT PROBLEM Facility Layout problem involves the location of departments (or sections) within the facility AND the arrangement of people and equipment within each department.

FACILITY LAYOUT PROBLEM The layout decision will certainly affect the Flow of materials, in-plant Transportation cost, equipment utilization, and general productivity and effectiveness of the business. Therefore, plant layout should be carefully arranged, AND It must satisfy specific objectives.

FACILITY LAYOUT PROBLEM Usually the layout is planned to minimize a particular criterion: For example, minimizing total traveling time, total cost, total delays, etc. There are also situations in which the layout may be designed to maximize a criterion: For example, maximize quality, flexibility, or space utilization.

Layout Types - Process Layout: - Fixed Layout: - Product Layout:

Process Layout Similar pieces of equipment that perform similar functions are grouped together. For example; all drill machines are grouped and placed together.

Product Layout The pieces of equipment required to make a Particular product are grouped together, as in an Automobile assembly line.

Fixed Layout The equipment is brought to the object being processed, and the object does not move. Example; house construction.

Layout Types The selection of the layout type depends on: 1) the firm’s operations strategy, 2) the forecast volume of production, 3) the physical characteristics of the product, 4) availability of the resources, and 5) the type of process technology that will be used.

Layout Types Regardless of the layout type selected, Today’s harsh competition forces manufacturer firms to build new facilities that can be easily transformed to other types of facilities. This means that the companies are becoming more flexible in changing their facility layouts in order to respond future needs of the organization.

Quantitative Models for Facility Layout Decisions Arranging people and equipment in a facility can quickly become complex. The greater the variety of ways in which products are carried through the facility, the greater the number of potential layouts.

Quantitative Models for Facility Layout Decisions When there are many alternatives to consider, the analytic models that we describe in the following are helpful.

Minimizing Communication Cost If there is considerable traffic between pairs of departments, a firm may want to Minimize the cost of inter-departmental travel.

Example Frontec Company wants to arrange Four of its departments in a Row so that the Total Distance Traveled between Departments is minimized. This part of the building will contain four departments arranged in a row.

Example Frontec wishes to minimize the total daily inter-departmental distance traveled. The number of daily communications between each pair of department is shown below:

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Example Assume that adjacent departments are 20 feet apart. We will use a trial-and-error approach to this problem. Assume that we selected the following configuration for the departments: A-B-C-D. For this configuration, Total communication cost (based on distance) is as follows:

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Example In terms of total daily communication distance, (B-A-C-D) is the preferred alternative. But the firm has to consider all of the 24 (4! = 4x3x2x1) possible configurations before it knows if this is the optimal configuration.

Example This trial-and-error approach becomes time-consuming as the number of departments increases AND It also becomes complex when the cost of communications vary between departments.

Systematic Layout Planning Systematic Layout Planning (SLP) is an organized approach to facility Layout planning.

Systematic Layout Planning The heart of SLP is the Activity Relationship Chart and Diagrams that neatly summarize vast amounts of quantitative and Qualitative information.

Example A small accounting Firm, GUNTAŞ Accounting, has rented Space in a new one-floor building. The firm has allocated 6000 square meter to its seven departments as follows:

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Example In the first step of Systematic Layout Planning, we analyze interactions between departments AND we assess the desirability of placing departments together.

Example The firm has carefully analyzed its operations to Determine the importance of Locating specific departments Close Together. The results of this analysis are summarized in the following Activity Relationship Chart:

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Example This Activity Relationship Diagram is essentially an Illustration of the Information Contained in the Activity Relationship Chart. All departments in this diagram are Represented by equal size boxes. The next step is to anticipate the space required for each Department.

Example Since the space assignments are given before, the following Activity Relationship Diagram shows the relative Sizes of Each Department:

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Example In this stage, there are no restrictions on the length and width of each department In the final step, we should develop and evaluate several alternative layouts, while keeping in mind the Practical Limitations.

Example Some examples of Practical Limitations in this case were as follows: 1- It is considered that offices for partners (2), the meeting room (7) and the reception area (1) should be close to each other. 2- It is important that the juniors (4) and the managers (3) be close together.

Example As a result of these limitations, An alternative floor plan is developed as follows:

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Example This floor plan may be revised many times until the best layout has been found. Usually departments are positioned one by one, Beginning with the department with the Highest A or E ratings. Systematic Layout Planning is essentially an organized Trial-and-Error Approach.

Example Therefore, unless all possible layouts are considered, There is no way to know if an Optimal Solution been Reached. However, there are a number of Heuristics that can be used to Generate good solutions Quickly. Heuristics: Trial-and-error solutions that do not give optimal solution but easy to apply.

Example Layout planning Heuristics are of two types: - Those which start with an initial layout and proceed to modify it (These are called Improvement Heuristics), and - Those which start the Layout analysis from scratch (Construction Heuristics.)

Example The most widely known algorithm requiring an Initial Layout developed by hand is the Computerized Relative Allocation of Facilities Technique (CRAFT). CRAFT was developed for situations in which Materials Handling Costs were a major consideration.

Example Therefore, its goal is to Minimize the Total Cost of Moving Items between Departments. It attempts to improve an Initial Layout by switching the locations of pairs of departments. It begins with one department, AND one by one Analyzes the effect on total travel cost of switching those departments.

Example While the Original CRAFT was used only for single-story buildings, An extension of CRAFT called SPACECRAFT can handle multistory buildings. Some examples of Construction Heuristics include CORELAP (Computerized Relationship Layout Planning) and ALDEP (Automated Layout Design Program).

Example These heuristics start with an empty floor area and proceed to fit departments. ALDEP can be used in a multistory building. It generates many alternative layouts.

Example CORELAP on the other hand, can lay out only single story buildings. Both programs use closeness codes defined in the Activity Relationship Charts.

Example A Final Note: In general, Because technologies change rapidly, facilities and technologies must be modified to suit the market requirements.

Example It is better to have Low-cost, extendable physical facilities Than to modify existing structures. These extendable facilities can be replaced with more suitable structures designed for the life of the changing products or services.

Storage and Warehouse Layouts In a storage Layout, The most important criterion is the Ease of Storage and Retrieval. Aisles in a storage need to be little wider than the equipment for moving and handling stock.

Storage and Warehouse Layouts And equipment should be selected that allows the Fullest use of the internal Height of the Building. There are differences between Automated and Manually picked store houses. In a storehouse using Automated Storage and Retrieval Systems (AS/RS),

Storage and Warehouse Layouts - There need to be no or little Light. - The aisles need to be wider than the largest dimension of the biggest stock item. - Buildings can be higher, and there no restrictions about the weights. - A crane is dedicated to each aisle, picking from either side. - Therefore, a crane breakdown means no access to the affected aisle until it is repaired.

Storage and Warehouse Layouts In a manual system, on the other hand, - Good lightening levels are required. - Heavy items should be stored at knee level or lower. - Storage package sizes should be no heavier than one person can handle.