Facility Layout Planning and Design Chapter 11 Sections

Facility Layout Planning and Design Chapter 11 Sections: 1. Types of Production Plant Layouts 2. Other Types of Layouts 3. Systematic Layout Planning Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Facility Layout Refers to the size and shape of a facility as well as the relative locations and shapes of the functional areas (e. g. , departments), equipment, workstations, storage spaces, aisles, and common areas (e. g. , restrooms) § Concerned with problems of § Laying out a new facility § Making changes in an existing facility § Also called plant layout § Usually associated with production plants Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Objectives in Layout Planning § § Efficient movement of materials and people Logical work flow and minimum travel distances Efficient utilization of space Safety and satisfaction of those who use the facility § Flexibility to meet changing future requirements § Advancing the operational mission of the facility Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Types of Production Plant Layouts 1. 2. 3. § Process layout Product layout Fixed-position layout Also: Hybrids of the three basic types Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Important Factors in Plant Layout § Q = production quantity - number of units of a given part or product that the facility produces § Low production - 1 to 100 units § Medium production - 100 to 10, 000 units § High production - 10, 000 to millions of units § P = product variety - number of different product designs or types made in the plant Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

P - Q Relationship in Plant Layout Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Process Layout in which equipment is arranged according to function § Suited to low and medium production quantities and medium to high product variety § Different parts or products are processed through different operations in batches § Each batch follows its own routing § No common work flow followed by all work units § Material handling activity is significant Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Process Layout Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Product Layout in which workstations and equipment are located along the line of flow of the work units § Suited to high production quantities and low product variety § Work units typically moved by powered conveyor § At each workstation, a small amount of the total work content is accomplished on each work unit § Each station specializes in its task, thus achieving high efficiency Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Product Layout for Assembled Product Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Comparisons Feature Annual Q Product variety Production rate Efficiency Labor skill Work-in-process Equipment Advantages Disadvantages Process Layout Low or medium Medium to high Low Skilled High WIP General purpose Versatility to deal with product variety Low production rate Batch production Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved. Product Layout High Low High Unskilled Lower WIP Special purpose High production rate High efficiency Risk of obsolescence Limited variety

Fixed-Position Layout in which product remains in one location during fabrication, and workers and equipment are brought to the product § Suited to low production quantities and high product variety § Reason for keeping product in one location: § Product is big and heavy § Typical plants: assembly and fabrication § Much manual labor § Equipment is portable or mobile Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Fixed-Position Layout Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Hybrid Layouts § Cellular - attempts to combine the best features of process and product layouts § Combinations of fixed position and either § Process layout or § Product layout Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Cellular Layout in which work units flow between stations, as in a production line, but each station can cope with a variety of part styles without the need for time-consuming changeovers § Combination of product and process layouts § Tries to combine efficiency of product layout with versatility of process layout § Neither objective is achieved perfectly, but it is more efficient than a process layout and more versatile than a product layout § Based on principles of group technology Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Cellular Layout Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Other Combination Layouts § Fixed-position and process layout § Shipyard - ships made in modules § Parts fabricated in process layout § Modules built in fixed-position layout § Fixed-position and product layout § Commercial airplanes (e. g. , Boeing 747) § Fabrication begins with fuselage and proceeds through 7 or so stations where specialized workers assemble parts and modules to airplane Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Layout Types for P-Q Combinations Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Other Types of Layouts § § Warehouses Projects Service facilities Offices Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Warehouse Layout § Principal function of warehouse layout = storage of merchandise, commodities, or other items § Must plan the layout for other functions also § Four main warehouse functions: § Receiving § Storing § Order picking § Shipping Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Warehouse Layout Centralized receiving and shipping in a single dock area Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Warehouse Layout Decentralized receiving and shipping to achieve flow-through in the storage facility Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Project Layout § Usually refers to construction project § Work teams and equipment are brought to the work site § Layout is temporary because project has scheduled completion date § Project layout vs. fixed-position layout: § Product is large and heavy § In fixed-position layout, when product is completed, it is transported away § In project layout, product remains, workers and equipment are transported away Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Service Facility Layouts § Most service layouts based on process layout § Personnel and equipment are organized according to function § Example: department store § Organized according to type of merchandise § Shoe department § Jewelry department, etc. § Efficient flow of people (customers) is sacrificed to maximize customer exposure to merchandise Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Office Layout § Usually an approximation of a process layout § Personnel are typically grouped according to function § Within a given department, a work flow pattern exists and can be used to determine proper locations of personnel and offices § Basic decisions about layout: § Walled offices vs. open office concept Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Walled Office Layout Characterized by many private offices with permanent walls defining the floor plan § Locations and sizes of offices related to position and importance of occupant § Top-level executive 425 sq ft § Middle-level executive 350 sq ft § Supervisor 200 sq ft § Office employee 75 to 100 sq ft* * Not necessarily private offices Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Open Office Concept Office layout consists of large open area § Modular furniture and partitions used to designate and separate workstations § Workers organized to promote efficient work flow § Advantages: § Lower construction costs § Easier supervision of employees § Flexibility to make changes in layout § Better control of heating, cooling, lighting § Improved communications among workers Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Levels of Detail in Plant Layout a) Site layout - shows building location on property b) Block layout - shows arrangement and sizes of departments in building c) Detailed layout - shows workstations and equipment in each department d) Workstation layout - indicates arrangement of equipment, workbench, WIP inventory, and worker floor space for each workstation type Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Levels of Detail in Layout Design Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Systematic Layout Planning § § Developed by Richard Muther Most widely used layout planning approach Most applicable to process layout design Most appropriate for designing a new plant (“green field” facility) Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Steps in SLP 1. Determine requirements and collect data 2. Analyze material flows 3. Define activity relationships and develop activity relationship chart 4. Construct activity relationship diagram 5. Determine space requirements 6. Construct space relationship diagram 7. Make adjustments and add allowances 8. Develop block layout 9. Develop detailed layout Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 1. Requirements and Data § Starting specifications in plant layout design: § Specific product or set of products will be produced § Particular set of manufacturing and/or assembly processes will be performed § Specified quantities of parts and products will be produced § Rarely are specifications for two plants the same Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Muther’s P-Q-R-S-T Requirements § P - product - what products and products § Q - quantity - how many of each product § R - routing - manufacturing processes through which parts and products will be routed § S - supporting services § Utilities, restrooms, offices, etc. § T - time issues: § How many shifts per week? § By when must the building project be completed? Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

P-Q Curve Shape of P-Q curve can provide information about the type of plant layout that will be required Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

P-Q Curve is a Pareto Chart The actual data in the P-Q curve represent discrete products Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

P-Q Curve for Process Layout Curve indicates that multiple products with medium quantities are produced Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

P-Q Curve for Product Layout P-Q curve indicates that one product is made in high quantities Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 2. Analyze Material Flows Possible charting techniques to analyze material flows: § Operation chart - shows sequence of processing, assembly, and inspection operations for products § Flow process chart - shows processing steps and other details for parts production § From-To chart - shows quantities and directions of material flows between departments § Part routing matrix - shows which operations each part is routed through during production Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 3. Activity Relationships Indicate relative need to place activities or departments in close proximity to each other § Defined by closeness ratings A - absolutely necessary for departments to be next to each other E - especially important I - important O - ordinary U - unimportant X - Undesirable to locate departments near each other Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Activity Relationship Chart Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Closeness Rating Factors 1. Material flow - most important, sometimes the only factor 2. Need for contact between personnel 3. Use of same equipment 4. Sharing of common records 5. Sharing of supervision or technical staff 6. Use of same utilities 7. High noise level 8. Emission of fumes, odors Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 4. Activity Relationship Diagram Graphical means of displaying the closeness ratings among pairs of activities (departments) § Uses nodes to represent activities § Nodes are connected by lines indicating the closeness ratings § Closeness ratings are identified by § Color § Different types of lines § Analyst attempts to rearrange nodes so that nodes with high closeness ratings are located near each other Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Activity Relationship Diagram Blocks represent departments Lines represent closeness ratings Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Revised Activity Relationship Diagram Blocks rearranged to bring departments with high closeness ratings closer together Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 5. Space Requirements § § Objective is to determine area requirements for each activity (department) Procedure: 1. List all workstation types § Identify by subscript i 2. Determine floor space requirement for each station type § Let Ai = area for station type i 3. Determine number of stations of each type ni = Min Int WLi / ATi Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Space Requirements 4. If workload for station i consists of multiple parts or products, WLi = Qij. Tcij where Qij = quantity of part type j, Tcij = cycle time of part type j 5. Determine total area required for each workstation type TAi = ni. Ai Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Space Requirements 6. Determine total are in each department by summing areas for all station types in that department DAk = TAi where DAk = area of department k and summation is carried out over all workstation types in department k Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 6. Space Relationship Diagram Extension of activity relationship diagram in which nodes representing departments are now assigned areas that are proportional to areas calculated in previous step § Shapes of nodes may be changed to fit the nodes into the diagram (e. g. , use rectangular blocks rather than round nodes) § But relative positions of blocks remain as in the last iteration of the activity relationship diagram Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Space Relationship Diagram Same diagram as before but block sizes are proportional to areas Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 7. Adjustments and Allowances § Personnel requirements - rest rooms, locker rooms, food services, plant entrances and exits § Material handling methods - may affect floor space and building height § Storage facilities - treat as separate department or add allowance § Aisle space - add a percentage allowance § Offices - for individual departments § Building features - walls, column locations § Site conditions - parking, landscaping Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Limitations § Budget - construction costs may impose limitation on building size § Building codes - may affect location of building on property as well as structural and utility details § Safety requirements - some included in building codes, others covered by OSHA § Existing building - if layout is planned around an existing building, then shape and size of building is a limitation on plant layout design Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Step 8. Develop Block Layout § Develop alternative layout plans based on space relationship diagram § Different shapes and aspect ratios § Evaluate alternatives § Select the best § Compromise between competing objectives, modifying considerations, and practical limitations Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Block Layout Rectangular building shape Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Block Layout Approximates space relationship diagram Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Evaluating the Layouts § Numerical scoring methods to evaluate the block layout: § Adjacency score § Layout efficiency rating Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Adjacency Score Computed by summing the numerical closeness rating values for all contacting pairs of departments where xij = adjacency variable (= 1 if common border, 0 if no common border), CRij = numerical value of closeness ratings (A = 4, E = 3, I = 2, O = 1, U = 0, X = -5) Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Layout Efficiency Rating LER = AS / ASmax where AS = adjacency score, and where CRij 0 = CRij if CRij > 0, and Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved. = 0 if

Step 9. Develop Detailed Layout Filling in the block layout with the details of how each department will be arranged § Locations and areas of workstations and equipment, aisles, department offices, storage areas, etc. § Layout design provides a check on the original calculations § If details do not fit into spaces correctly, then there may be an error in original space calculations Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Design of Product Layouts § Product layout can be considered as one large department to accomplish the step-by-step production of the product § Product is usually an assembly, and the layout is usually an assembly line § Where there is more than one department, each department can be designed independently, so long as line-of-flow is consistent at connection points Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Number of Workstations nm = Min Int where nm = number of manual stations, Twc = work content time of product, Er = repositioning efficiency, Eb = line balancing efficiency, M = manning level, and Tc = cycle time of line If there automated stations, n = nm + na where n = total number of stations, na = number of automated stations Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.

Plant Area § Line length L = § Working area A = § To this area must be added § Allowances for aisles § Storage areas to supply the line with parts § Space for personnel requirements Work Systems and the Methods, Measurement, and Management of Work by Mikell P. Groover, ISBN 0 -13 -140650 -7. © 2007 Pearson Education, Inc. , Upper Saddle River, NJ. All rights reserved.