3Introduction Process selection Major implications Deciding on the way production of goods or services will be organizedMajor implicationsCapacity planningLayout of facilitiesEquipmentDesign of work systems
4Process Selection and System Design Figure 6.1ForecastingProduct and Service DesignTechnological ChangeCapacity PlanningProcess SelectionFacilities and EquipmentLayoutWork Design
5Process Strategy Key aspects of process strategy Capital intensive – equipment/laborProcess flexibilityAdjust to changesDesignVolumetechnology
6Process Selection Variety Flexibility Volume How much What degree Expected outputBatchJob ShopRepetitiveContinuous
7Process Types Job shop Batch Repetitive/assembly line Continuous Small scaleBatchModerate volumeRepetitive/assembly lineHigh volumes of standardized goods or servicesContinuousVery high volumes of non-discrete goods
9Product – Process Matrix Figure 6.2 (cont’d)DimensionJob varietyVery HighModerateLowVery lowProcess flexibilityUnit costVolume of outputHigh
10AutomationAutomation: Machinery that has sensing and control devices that enables it to operateFixed automationProgrammable automation
11Automation Computer-aided design and manufacturing systems (CAD/CAM) Numerically controlled (NC) machinesRobotManufacturing cellFlexible manufacturing systems(FMS)Computer-integrated manufacturing (CIM)
12Facilities LayoutLayout: the configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system
13Importance of Layout Decisions Requires substantial investments of money and effortInvolves long-term commitmentsHas significant impact on cost and efficiency of short-term operations
14The Need for Layout Decisions Inefficient operationsFor Example:High CostBottlenecksChanges in the designof products or servicesThe introduction of new products or servicesAccidentsSafety hazards
15The Need for Layout Design (Cont’d) Changes inenvironmentalor other legalrequirementsChanges in volume ofoutput or mix ofproductsChanges in methodsand equipmentMorale problems
16Basic Layout Types Product layouts Process layouts Fixed-Position layoutCombination layouts
17Basic Layout Types Product layout Process layout Fixed Position layout Layout that uses standardized processing operations to achieve smooth, rapid, high-volume flowProcess layoutLayout that can handle varied processing requirementsFixed Position layoutLayout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed
18Product Layout Figure 6.4 Raw materials or customer Station1Station2Station3Station4Finished itemMaterialand/or laborMaterialand/or laborMaterialand/or laborMaterialand/or laborUsed for Repetitive or Continuous Processing
19Advantages of Product Layout High rate of outputLow unit costLabor specializationLow material handling costHigh utilization of labor and equipmentEstablished routing and schedulingRouting accounting and purchasing
20Disadvantages of Product Layout Creates dull, repetitive jobsPoorly skilled workers may not maintain equipment or quality of outputFairly inflexible to changes in volumeHighly susceptible to shutdownsNeeds preventive maintenanceIndividual incentive plans are impractical
21A U-Shaped Production Line Figure 6.612345678910InOutWorkers
22Used for Intermittent processing Process LayoutFigure 6.7Process Layout(functional)Dept. ADept. BDept. DDept. CDept. FDept. EUsed for Intermittent processingJob Shop or Batch
23Used for Repetitive Processing Repetitive or Continuous Product LayoutFigure 6.7 (cont’d)Product Layout(sequential)WorkStation 1Station 2Station 3Used for Repetitive ProcessingRepetitive or Continuous
24Advantages of Process Layouts Can handle a variety of processing requirementsNot particularly vulnerable to equipment failuresEquipment used is less costlyPossible to use individual incentive plans
25Disadvantages of Process Layouts In-process inventory costs can be highChallenging routing and schedulingEquipment utilization rates are lowMaterial handling slow and inefficientComplexities often reduce span of supervisionSpecial attention for each product or customerAccounting and purchasing are more involved
26Cellular Layouts Cellular Production Group Technology Layout in which machines are grouped into a cell that can process items that have similar processing requirementsGroup TechnologyThe grouping into part families of items with similar design or manufacturing characteristics
27Functional vs. Cellular Layouts Table 6.3DimensionFunctionalCellularNumber of moves between departmentsmanyfewTravel distanceslongershorterTravel pathsvariablefixedJob waiting timesgreaterThroughput timehigherlowerAmount of work in processSupervision difficultyScheduling complexityEquipment utilization
28Other Service Layouts Warehouse and storage layouts Retail layouts Office layouts
29Design Product Layouts: Line Balancing Line Balancing is the process of assigningtasks to workstations in such a way that the workstations have approximately equal time requirements.
30Cycle Time Cycle time is the maximum time allowed at each workstation tocomplete its set of tasks on a unit.
32Determine the Minimum Number of Workstations Required
33Precedence Diagram a b c d e Figure 6.10Precedence diagram: Tool used in line balancing to display elemental tasks and sequence requirementsA Simple PrecedenceDiagramabcde0.1 min.0.7 min.1.0 min.0.5 min.0.2 min.
34Example 1: Assembly Line Balancing Arrange tasks shown in Figure 6.10 into three workstations.Use a cycle time of 1.0 minuteAssign tasks in order of the most number of followers
35Example 1 Solution Workstation Time Remaining Eligible Assign Task Revised Time RemainingStation Idle Time11.00.90.2a, ccnonea-2b0.030.50.3de
36Calculate Percent Idle Time Efficiency = 1 – Percent idle time
37Some Heuristic (intuitive) Rules: Line Balancing RulesSome Heuristic (intuitive) Rules:Assign tasks in order of most following tasks.Count the number of tasks that followAssign tasks in order of greatest positional weight.Positional weight is the sum of each task’s time and the times of all following tasks.
41Designing Process Layouts Information Requirements:List of departmentsProjection of work flowsDistance between locationsAmount of money to be investedList of special considerationsLocation of key utilities
42Example 3: Interdepartmental Work Flows for Assigned Departments Figure 6.1213230170100ABC
43Author’s note:The following three slides are not in the 8e, but I like to use them for alternate examples.
44Process Layout - work travels to dedicated process centers MillingAssembly & TestGrindingDrillingPlating