2 Process design Process design Operations strategy ImprovementPlanning and controlProcess designSupply network designLayoutand flowProcess technologyPeople, jobs and organizationProduct/ service designOperations management
3 Key operations questions In Chapter 4 – Process design – Slack et al. identify the following key questions:What is process design?What objectives should process design have?How does volume and variety affect process design?How are processes designed in detail?
4 Nature and purpose of the design activity Products, services and the processes which produce them all have to be designed.Decisions taken during the design of a product or service will have an impact on the decisions taken during the design of the process which produces those products or services and vice versa.
5 The design of products/services and processes are interrelated and should be treated together Products and services should be designed in such a way that they can be created effectively.Product/service design has an impact on the process design and vice versa.Processes should be designed so they can create all products and services which the operation is likely to introduce.
6 The overlap of activities is greater in service design In manufacturing operations overlapping the activities of product and process design is beneficial.In most service operations the overlap between service and process design is implicit in the nature of service.
7 The Smart car uses environmentally friendly design principles
8 Process mapping symbols Delay (a wait, e.g. for materials)Operation (an activity that directly adds value)Inspection (a check of some sort)Transport (a movement of something)Storage (deliberate storage, as opposed to a delay)Process mapping symbols derived from ‘Scientific Management’Decision (exercising discretion)Process mapping symbols derived from Systems AnalysisDirection of flowInput or Output from the processActivityBeginning or end of process
9 Designing processesThere are different ‘process types’.Process types are defined by the volume and variety of ‘items’ they process.Process types go by different names depending on whether they produce products or services.
10 Manufacturing process types Process tasksProcess flowDiverse/ complexRepeated/ dividedIntermittentContinuousProjectHighJobbingBatchVarietyMassContin-uousLowLowVolumeHigh
11 Project processesOne-off, complex, large scale, high work content ‘products’Specially made, every one customizedDefined start and finish: time, quality and cost objectivesMany different skills have to be coordinated.
12 Jobbing processesVery small quantities: ‘one-offs’, or only a few requiredSpecially made. High variety, low repetition. ‘Strangers’ every one customizedSkill requirements are usually very broadSkilled jobber, or team, complete whole product.
13 Batch Processes Higher volumes and lower variety than for jobbing Standard products, repeating demand. But can make specialsSpecialized, narrower skillsSet-ups (changeovers) at each stage of production.
14 Mass (line) processes Higher volumes than batch Standard, repeat products (‘runners’)Low and/or narrow skillsNo set-ups, or almost instantaneous ones.
15 Continuous processesExtremely high volumes and low variety: often single productStandard, repeat products (‘runners’)Highly capital-intensive and automatedFew changeovers requiredDifficult and expensive to start and stop the process.
16 Service process types Process tasks Process flow High Diverse/ complexRepeated/ dividedIntermittentContinuousHighProfessional serviceService shopVarietyMass serviceLowLowVolumeHigh
17 Professional service High levels of customer (client) contact. Clients spend a considerable time in the service process.High levels of customization with service processes being highly adaptable.Contact staff are given high levels of discretion in servicing customers.People-based rather than equipment-based.
18 Service shops Medium levels of volumes of customers Medium, or mixed, levels of customer contactMedium, or mixed, levels of customizationMedium, or mixed, levels of staff discretion.
19 Mass service High levels of volumes of customers Low to medium levels of customer contactLow, or mixed, levels of customizationLow, or mixed, levels of staff discretion.
20 Deviating from the ‘natural’ diagonal on the product–process matrix has consequences for cost and flexibilityProjectJobbingBatchMassContinuousManufacturing operations process typesVarietyVolumeProfessionalserviceServiceshopMassService operations process typesThe ‘natural’ line of fit of process to volume/variety characteristicsNoneMore process flexibility than is needed so high costLess process flexibility than is needed so high costNone9
21 Deviating from the ‘natural’ diagonal on the product–process matrix has consequences for cost and flexibility (Continued)VarietyVolumeNoneThe ‘natural’ line of fit of process to volume/variety characteristicsOld processOld process new productNew process new product9
22 Standard sandwich process Customized sandwich – old processRaw materialsStored sandwichesMove to outletsStored sandwichesTake paymentAssemblyCustomer requestSellStandard sandwich process
23 Customized sandwich – old process (Continued) Raw materialsTake paymentCustomer requestAssembly
24 Higher level process map The outline process of making and selling customized sandwichesPrepareAssemble as requiredTake paymentThe operation of making and selling customized sandwichesSandwich materials and customersCustomers ‘assembled’ to sandwichesBread and base fillingStored ‘bases’FillingsAssemble whole sandwichCustomer requestUse standard ‘base’?Assemble from standard ‘base’NoYesThe detailed process of assembling customized sandwiches
25 Customized sandwich - new process Assemble whole sandwichAssembly of ‘sandwich bases’Customer requestUse standard ‘base’?NoYesTake paymentFillingsBread and base fillingStored ‘bases’Assemble from standard ‘base’
26 Flow process charts for processing expense Send to accounts receivableReports to batch controlReports filedConfirm paymentReport arrivesStamp and date reportSend cash to receipt deskWait for processingCheck expenses reportCheck employee recordCheck advance paymentSend to account payableAttach payment voucherCollect retorts into batchCheck against rulesBatch control numberCheck payment voucherLog reportBatch to audit deskWait for batchingBatch of reports loggedCopy of reports to filingDescription of activityTotals8124567910318111214151617192013262223242521Payment voucher to keyingBeforeReports to batch controlReports filedPayment voucher to keyingConfirm paymentReport arrivesStamp and date reportCheck expenses reportWait for processingCheck reports and vouchersAttach payment voucherCollect retorts into batchBatch control numberBatch to audit deskWait for batchingCopy of reports to filingDescription of activityTotals812456791031112141513After
27 Throughput (TH) = Work In Process (WIP) x Cycle Time (CT) Little’s law (a really quite useful law)Throughput (TH) = Work In Process (WIP) x Cycle Time (CT)Cycle time = 2 minsWIP = 10Throughput time = ?Throughput time = 10 × 2 minsThroughput time = 20 mins
28 Throughput (TH) = Work In Process (WIP) x Cycle Time (CT) Little’s law (a really quite useful law) (Continued)Throughput (TH) = Work In Process (WIP) x Cycle Time (CT)Need to mark 500 exam scripts in 5 days (working 7 hours a day). Takes 1 hour to mark a script. How many markers are needed?Throughput time = 5 days × 7 hours = 35 hours35 hours = 500 scripts × Cycle timesCycle time = hours500 scripts= 0.07 hoursNumber of markers = Work content = 1 hour =Cycle time0.07
29 Throughput efficiency Throughput efficiency is the work content of whatever is being processed as a percentage of its throughput timeThroughput efficiency =Work contentThroughput time× 100
30 Arrival frequency (demand) X5–15 minsArrival frequency (demand)Processing timeUtilization = <100% % Q = >0Throughput time and capacity utilisationArrival frequency (demand)XUtilization = 100 % Q = infinity9 minsXUtilization = 50 % Q = 020 minsX10 minsUtilization = 100 % Q = 030 mins10 minsProcessing timeUtilization = % Q = 0HighHigh utilization but long throughput timesLow utilization but short throughput timesReduce process variabilityProcess throughput time(or inventory)Average length of queueXXLowX20%40%60%80%100%Capacity utilization
31 Process utilization, waiting time and variability High utilization but long waiting timeAverage number of units waiting to be processedDecreasing variabilityAverage number of units waiting to be processedReduction in process variabilityXShort waiting time but low utilizationZY102030405060708090100102030405060708090100UtilizationUtilization(a) Decreasing variability allows higher utilization without long waiting times.(b) Managing process capacity and/or variability.