CHAPTER 3 FLOW, SPACE, AND ACTIVITY RELATIONSHIPS. In determining the requirement of a facility, three important consideration are: Flow

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1 1 CHAPTER 3 FLOW, SPACE, AND ACTIVITY RELATIONSHIPS Asst.Prof.Dr.BusabaPhruksaphanrat IE333 Industrial Plant Design Introduction 2 In determining the requirement of a facility, three important consideration are: Flow Depends on lot sizes, unit load sizes, material handling equipment and strategies, layout arrangement, and building configuration Space Is a function of lot sizes, storage system, production equipment type and size, layout arrangement, building configuration, organization policies, material handling equipment, office, cafeteria, and restroom design.

2 Introduction 3 Activity relationships Defined by material or personnel flow, environmental considerations, organization structure, continuous improvement methodology, control issues and process requirements Impact of modern manufacturing approaches on flow, space and activity relationships should be investigate. Ex. Decentralized management, cellular manufacturing, lean structure, small lot purchasing, etc. Departmental planning 4 Production planning departments are collections of workstations to be grouped together during the facilities layout process. Planning departments may be determined by combining workstations that perform like functions. Depending on volume-variety. The resulting production planning department may be referred to as production line department.

3 5 Low and sporadic demand exists for a product that is very large and awkward to move. The workstations should be combined into a planning department that includes all workstations required to produce the product. This type may be referred to as a fixed materials location department. Medium demand for a medium number of similar components. Similar components form a family of components that may be produced via a group of workstations. This type is referred to as a product family department. 6 Planning department based on the combination of workstations containing similar processes is referred to as process department.

4 7 Classification of layout 8 Product planning department product layout Production family planning department group technology layout Process layout process layout Fixed materials location planning department fixed location layout

5 9 The difficulty in defining process departments is in the interpretation of the word similar. The determination of which workstations are to be considered similar depends on not only the workstations but also the relationships among workstations and between workstations and the overall facility. A systematic approach should be used in combining workstations into departments. Table 3.1 summarizes the bases for combining workstations into planning departments. 10

6 11 Traditionally, support, administrative, and service planning departments have been treated as process departments. Organizations using modern manufacturing approaches are combining production, support, administrative, and service planning departments to create integrated production-supportadministrative-service planning departments. Manufacturing cells 12 Cellular manufacturing involves the use of manufacturing cells. The manufacturing cells can be formed in a variety of ways, grouping of m/cs, employees, materials, tooling, and MH and storage equipment families of parts to produce. It is often associated with JIT, TQM and lean manufacturing concepts and techniques. Successful implementation of manufacturing cells requires addressing selection, design, operation, and control issues.

7 13 Selection = the identification of m/c and part types for a particular cell. Cell design = layout and production and MH requirements. Operation of a cell = determination of lot sizes, scheduling, number of operators, type of production control (push & pull). Control of a cell = methods used to measure the performance of the cell. 14 Several approaches have been proposed to address selection issues of manufacturing cells. The most popular approaches are classification and coding, production flow analysis, clustering techniques, heuristic procedures, and mathematical models.

8 15 Classification is the grouping of parts into classes or part families based on design attributes and coding is the representation of these attributes by assigning numbers or symbols to them. Production flow analysis is the procedure for forming part families by analyzing the operation sequences and the production routing of a part or component through the plant 16 Clustering methodologies are used to group parts together so they can be processed as a family. direct clustering algorithm (DCA) Heuristic procedures- assign m/c to cell based on work load factors and assigns parts to cells based on the percentage of operations of part processed within a cell. Mathematical models- branch and bound method

9 DCA methodology 17 Step 1: order the rows and columns. Sum the 1s in each column and in each row of the machine-part matrix. Order the rows (top to bottom) in descending order and order the columns (left to right) in ascending order of the number of 1s in each. Where ties exist, break the ties in descending numerical sequence. Example

10 19 Step 2: Sort the columns. Beginning with the first row of the matrix, shift to the left of the matrix all columns having a 1 in the first row. Continue the process row-by-row until no further opportunity exists for shifting columns. Step 3: Sort the rows. Column-by-column, beginning with the left most column, shift rows upward when opportunities exist to form blocks of 1s. Step 4: Form cells. Look for opportunities to form cells such that all processing for each part occurs in a single cell f03_04

11 21 22 Example 2

12 a 3b

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14 Activities relationships 27 The primary relationships considered are Organizational relationships Flow relationships Control relationships Environmental relationships Process relationships Organizational relationship 28 Influenced by span of control and reporting relationships Usually represented formally by an organization chart

15 Flow relationships 29 Flow of materials, people, equipment, information, and money. Discrete flow processes Continuous flow processes A flow process may be described in terms of the subject of flow, the resources that bring about flow, and the communications that coordinate the resources. 30 Subject of flow: item The resources that bring about flow : processing and transporting facility required to accomplish the required flow The communications that coordinate the resources: procedures

16 31 a) Production line departments b) Fixed materials location planning departments 32

17 33 Flow of materials into a manufacturing facility => Material management system The subjects of material management systems are the materials, parts, and supplies purchased. The resources of material management systems includes: The production control and purchasing functions The vendors The transportation and MH The receiving, storage, and accounting functions 34 The communications within material management systems include production forecasts, inventory records, stock requisitions, purchase orders, move tickets, receiving reports, kanbans, EDI, order payment, etc.

18 35 36 If the flow of materials, parts, and supplies within a manufacturing facility is to be the subject of the flow process => material flow system. The subjects of material flow systems are the materials, parts, and supplies used. The resources of material flow system included: The production control and quality control departments The manufacturing, assembly, and storage departments The MH equipment require to move materials, parts, and supplies The WH

19 37 Communication within the material flow system Includes: production schedules, work order releases, move tickets, kanbans, bar code, route sheets, assembly charts, and warehouse records. 38

20 39 If the flow of products from a manufacturing facility is to be the subject of the flow, the flow process => the physical distribution system The subject of physical distribution systems are the finished goods produced. The resources of physical distribution systems include: Customer The sales and accounting departments and warehouses The material handling and transportation equipment required to move the finished product The distributors of the finished product 40 Communications within the physical distribution system include: sales orders, packing lists, shipping reports, shipping releases, kanbans, EDI invoices, and bills of lading.

21 41 42 The material management, material flow, and physical distribution system may be combined into one overall flow system. Such as overall flow process is referred to as the logistics system.

22 Flow patterns 43 Flow within workstations Motions studies and ergonomics considerations Should be simultaneous, symmetrical, natural, rhythmical and habitual. Flow within departments Depend on type of department Flow between departments Overall flow Flow within departments 44 In a product and product family department, the flow of work Follows the product flow.

23 Flow within department 45 In a process dept., little flow should occur b/w workstations within departments. Flow typically occurs b/w workstations and aisles Flow between department 46 An important consideration in combining the flow patterns is the location of entrance and exit.

24 47 Flow planning 48 effective flow = flow patterns + adequate aisles Effective flow within a facility includes the progressive movement of materials, information, or people b/w departments. Effective flow within a department involves the progressive movement of materials, information, or people b/w workstations. Effective flow within a workstation involves the progressive movement of materials, information, or people through the workstation.

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26 51 52 The work simplification approach to material flow Eliminating flow by planning for the delivery of materials, information, or people directly to the point of ultimate use and eliminate intermediate steps Minimizing multiple flows by planning for the flow between two consecutive points of use to take place in as few movements as possible, preferable one Combining flows and operations wherever possible by planning for the movement of materials, information, or people to be combined with a processing step

27 53 The principle of minimizing the cost of flow Minimize manual handling by minimizing walking, manual travel distances and motions Eliminate manual handling by mechanizing or automating flow to allow workers to spend full time or their assigned tasks Measuring flow 54 Quantitative measures may includes piece per hour, moves per day, or pounds per week. Qualitative measures may range from an absolute necessity that two departments be close to each other to a preference that two departments not be close to each other.

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29 57 Quantitative flow measurement (from-to chart) Constructing a from-to chart List all departments down the row and across the column following the overall flow pattern 58

30 59 Establish a measure of flow for the facility that accurately indicates equivalent flow volumes. If the items moved are equivalent with respect to ease of movement, the number of trips may be recorded in the from-to chart. If the item moved vary in size, weight, value, risk of damage, shape, and so on, then some common unit of measure may be established so that the quantities recorded in the from-to chart represent the proper relationships among the volumes of movement 60 Based on the flow paths for the items to be moved and the established measure of flow, record the flow volumes in the from-to chart

31 Example 4 61 A firm produce three components 1 and 2 have the same size and weight and are equivalent with respect to movement. Component 3 is almost twice as large and moving two units of either component 1 or 2 is equivalent to moving 1 unit of component 3. The departments included in the facility are A, B, C, D and E. The overall flow path is A-B-C-D-E. The quantities to be produced and the component routings are as follows: 62 Component Production quantities (per day) Routing 1 30 A-C-B-D-E 2 12 A-B-D-E 3 7 A-C-D-B-E

32 Qualitative flow measurement 63 Muther method: using closeness relationships value 64 A relationship chart may be constructed as follows: 1. List all departments on the relationship chart. 2. Conduct interviews or surveys with persons from each department listed on the relationship chart and with the management responsible for all departments. 3. Define the criteria for assigning closeness relationships and itemize and record the criteria as the reasons for relationship values on the relationship chart

33 65 4. Establish the relationship value and the reason for the value for all pairs of departments 5. Allow everyone having input to the development of the relationship chart an opportunity to evaluate and discuss changes in the chart. 66

34 Space requirements 67 Space requirements should be developed from the ground up In determining space req. for warehousing activities, inventory levels, storage units, storage methods and strategies, equipment req., building constraints, and personnel req. must be considered. In manufacturing and office should be determined first for individual workstations; next, departmental req. should be determined, based on the collection of workstations in the department. 68 For modern manufacturing, space requirement are being reduced because 1. Smaller lot 2. Decentralized storage areas 3. Less inventories 4. More efficient layout 5. Companies are downsizing 6. Offices are shared and telecommuting is used

35 Workstation specification 69 The equipment space for a workstation Equipment --- from data sheets Machine travel----multiplying total width (static width plus maximum travel to the left and right) by total depth (static depth plus maximum travel toward and away from the operator) Machine maintenance area Plant services area 70 The materials areas for a workstation Receiving and storing inbound materials In-process materials Storing outbound materials an shipping Storing and shipping waste and scrap Tools, fixtures, jigs, dies, and maintenance materials Dimensions of the unit loads to be handle and the flow of material through the m/c must be known. Additional space for in-process materials, space for the removal of waste and scrap.

36 Personal area for workstation 71 The operator Material handling Operator ingress and egress Factors to be considered 72 Workstations should be designed So the operator can pick up and discharge materials without walking or making long or awkward reaches. For efficient and effective utilization of the operator To minimize the time spent manually handling materials To maximize operator safety comfort and productivity To minimize hazards, fatigue, and eye strain

37 73 Department specification 74 Departmental area req. = the sum of the area req. for the individual workstations to be included in a department. Additional space is required within each department for material handling within the department. The space requirement for aisles can be approximated.

38 75 Aisle arrangement 76

39 77 Visual management and space requirements Identification, housekeeping and organization Visual document Visual production maintenance, inventory and quality control Performance measurement Progress status 78