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Chapter 6 Process Selection and Facility Layout. Process selection Deciding on the way production of goods or services will be organized Major implications.

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Presentation on theme: "Chapter 6 Process Selection and Facility Layout. Process selection Deciding on the way production of goods or services will be organized Major implications."— Presentation transcript:

1 Chapter 6 Process Selection and Facility Layout

2 Process selection Deciding on the way production of goods or services will be organized Major implications Capacity planning Layout of facilities Equipment Design of work systems Introduction

3 Forecasting Product and Service Design Technological Change Capacity Planning Process Selection Facilities and Equipment Layout Work Design Process Selection and System Design

4 Variety How much Flexibility What degree Volume Expected output Job Shop Batch Repetitive Continuous Process Selection

5 Types of Operations INCREASED VOLUME Project/ Job Shop Unit or Batch Mass/ Assembly Continuous

6 Process Design Project Processes (Fixed Position) Intermittent Flow Processes (Batch Shops) Continuous Flow Processes (Flow Shops) Processing Industries (Continuous)

7 Job Shop (Fixed Position) People and material move Have limited duration Small scale Examples Housing Ship building Dam Appliance Repair

8 Intermittent Flow Processes (Batch Shops) No pattern exists between process of different products Appropriate to service organizations Moderate volume Example: Machine Shops Auto Repair Shops Commercial Bakery Classroom Lecture

9 Continuous Flow Processes (Flow Shops) Sequences are the same (Standard Routes) High volumes of standardized goods or services Examples: Assembly Lines Car Wash

10 Processing Industries (Continuous Flow) One primary input (gas, wheat, etc) is converted to multiple outputs Very high volumes of non-discrete goods Example: Petroleum Chemicals Food Industries

11 Process Characteristics CharacteristicsProjectIntermittentContinuous PRODUCT Order Type Single UnitBatch Continuous or large batch Flow of Product NoneJumbledSequence Product Variety Very HighHighLow Market type UniqueCustomMass Volume Single UnitMediumHigh

12 Process Characteristics CharacteristicsProjectIntermittentContinuous CAPITAL Inventory MediumHighLow Equipment General Purpose Special Purpose LABOR Skills High Low Task Type Non-routine Repetitive

13 Process Characteristics CharacteristicsProjectIntermittentContinuous CONTROL Production Difficult Easy Quality Difficult Easy Inventory Difficult Easy EQUIPMENT General Purpose Special Purpose

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16 Automation: Machinery that has sensing and control devices that enables it to operate Fixed automation Programmable automation Automation

17 Computer-aided design and manufacturing systems (CAD/CAM) Numerically controlled (NC) machines Robot Manufacturing cell Flexible manufacturing systems(FMS) Computer-integrated manufacturing (CIM) Automation

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19 Functional Areas Being Linked to Manage the Flow of Information Design Handling of Materials Storage and Retrieval of Information Control of Machine Tools

20 Design CAD No longer limited to the top, side and front views Can observe the rotation of the part about any axis on the screen Generally, improves productivity in the drafting room by a factor of 3 or more At GM, the redesign of a single auto model requires 14 months instead of 24 months The time needed to design custom values reduced from six months to one

21 Handling of Materials Data processing technology can be applied to the control of 3 general kids of machines in the factory: Machines that store, retrieve, or transport materials Machines that process the materials Robots

22 Handling of Materials Automatic storage and retrieval systems transfer pallets of material into or out of storage rack up to 100 feet high Mini Loaders Hold drawers of small parts Automatic Warehouse Automatic shuttle takes the place of the fork-lift truck and its human operations

23 Storage and Retrieval of Information GT The formation of part families based on design or manufacturing similarities (or both) Classification of parts speed up the design of similar parts in the company Only 20% of the parts actually need new design. 40% could be built from an existing design and the other 40% could be created by modifying an existing design. Automatic guided vehicle

24 Control of Machine Tools NC Machine tools run by programs DNC Direct numerically controlled machine tools Several computerized, NC machine tools are linked by a hierarchy of computers

25 Control of Machine Tools FMS Flexible Manufacturing System It consists of an integrated collection of: Automated Production Processes NC Robots A material transport system An automated transfer line Robots

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27 Control of Robots Robots A programmable machine capable of moving materials and performing repetitive tasks. Main features: They are flexible They eliminate the need for operators Applications Loading and unloading of machine tools Jobs that are dirty, hazardous, unpleasant, or monotonous

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30 The Operating Capabilities of the Factory of the Future Economic order quantity approaches 1 Variety has no cost penalty (economy of slope) Rapid response to changes in product design, market demand, and production mix Unmanned and continuous operation is standard Consistent high levels of quality and accuracy and repeatability introduce higher levels of certainty into the production planning and control activity

31 Layout: the configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system Facilities Layout

32 Requires substantial investments of money and effort Involves long-term commitments Has significant impact on cost and efficiency of short-term operations Importance of Layout Decisions

33 Product layout Layout that uses standardized processing operations to achieve smooth, rapid, high- volume flow Process layout Layout that can handle varied processing requirements Fixed Position layout Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed Basic Layout Types

34 Raw materials or customer Finished item Station 2 Station 2 Station 3 Station 3 Station 4 Station 4 Material and/or labor Station 1 Material and/or labor Material and/or labor Material and/or labor Used for Repetitive or Continuous Processing Product Layout

35 High rate of output Low unit cost Labor specialization Low material handling cost High utilization of labor and equipment Established routing and scheduling Routing accounting and purchasing Advantages of Product Layout

36 Creates dull, repetitive jobs Poorly skilled workers may not maintain equipment or quality of output Fairly inflexible to changes in volume Highly susceptible to shutdowns Needs preventive maintenance Individual incentive plans are impractical Disadvantages of Product Layout

37 Assembly Line Balancing Cycle time The time required to produce one part is called the cycle time, or the maximum time allowed at any one work station Assembly Line Balancing Given a cycle time, find the minimum number of work stations or minimize the cycle time for a given number of work stations

38 Assembly Line Balancing - Example TaskTime (min)Immediate Predecessors A B0.3A C0.2A D0.25A E0.15B,C F0.3D,E Total1.4

39 Assembly Line Balancing

40 CYCLE TIME.30  C  1.40 C = productive time/output rate C = (8hr x 60min) =.5 min 960 Number of work stations, N = total time/C N = 140 = 2.8 =3.5

41 Solution to Assembly Line Balancing Problem StationTasks AssignedTotal Task TimeIdle Time 1A, B0.50 2C, D E, F TOTAL1.40.1

42 Assign tasks in order of most following tasks. Count the number of tasks that follow Assign tasks in order of greatest positional weight. Positional weight is the sum of each task’s time and the times of all following tasks. Some Heuristic (intuitive) Rules: Line Balancing Rules

43 Assembly Line Balancing Solution Line Efficiency = Total Work Content C x N Efficiency = 1.40 =.93 or 93%.5 x 3 Balance Delay = 1 – efficiency = = 7%

44 cd abe fgh Example 2

45 Station 1Station 2Station 3Station 4 ab e f d g h c Solution to Example 2

46 In Out Workers A U-Shaped Production Line

47 Process Layout (functional) Assume we have the following departments: Accounting (A) Production Planning (P) Customer Service (C) Sales (S) What arrangement would be better?

48 AP CS SC AP Used for Intermittent processing Job Shop or Batch

49 Intermittent Process Criteria Desirability ranking Volume of interaction Cost of interaction Distance Time Safety Facility Limitations

50 Can handle a variety of processing requirements Not particularly vulnerable to equipment failures Equipment used is less costly Possible to use individual incentive plans Advantages of Process Layouts

51 In-process inventory costs can be high Challenging routing and scheduling Equipment utilization rates are low Material handling slow and inefficient Complexities often reduce span of supervision Special attention for each product or customer Accounting and purchasing are more involved Disadvantages of Process Layouts

52 Cellular Production Layout in which machines are grouped into a cell that can process items that have similar processing requirements Group Technology The grouping into part families of items with similar design or manufacturing characteristics Cellular Layouts

53 Process Layout - work travels to dedicated process centers Milling Assembly & Test Grinding Drilling Plating Process Layout - Example

54 Gear cutting Mill Drill Lathes Grind Heat treat Assembly Functional Layout

55 Assembly Lathe Mill Drill Heat treat Heat treat Heat treat Gear cut Gear cut Grind Cellular Manufacturing Layout – Group Technology


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