Capacity and Facilities

Facilities

Capacity and Facilities (Layout)CapacityMaximum capability to produceCapacity planningestablishes overall level of productive resources for a firm3 basic strategies for timing of capacity expansion in relation to steady growth in demand (lead, lag, and average)

Capacity Expansion Strategies

CapacityCapacity increase depends onvolume and certainty of anticipated demandstrategic objectivescosts of expansion and operationBest operating level% of capacity utilization that minimizes unit costsCapacity cushion% of capacity held in reserve for unexpected occurrencesEconomies of ScaleUnit cost decreases as output volume increasesfixed costs can be spread over a larger number of unitsproduction or operating costs do not increase linearly with output levelsquantity discounts are available for material purchasesoperating efficiency increases as workers gain experienceBest Operating Level for a Hotel

Objectives of Facility LayoutMinimize material-handling costsUtilize space efficientlyUtilize labor efficientlyFacilitate communication and interactionReduce manufacturing cycle timeReduce customer service timeEliminate wasted or redundant movementObjectives of Facility LayoutFacilitate entry, exit, and placement of material, products, and peopleIncorporate safety and security measuresPromote product and service qualityEncourage proper maintenance activitiesProvide a visual control of activitiesProvide flexibility to adapt to changing conditionsIncrease capacityBasic LayoutsProcess layoutsgroup similar activities together according to process or function they performProduct layoutsarrange activities in line according to sequence of operations for a particular product or serviceFixed-position layoutsare used for projects in which product cannot be moved

Process layout A process layout is characteristic of job shops production, which serve different customers with different needsThe volume of each customer is low and sequence of operations required to complete a customers order vary considerablyGrouping of like machines in one department

A quantity of material is issued to a machine which performs the first operation. This machine may be situated anywhere in the factory.For the next operation, a different machine may be required, which may be situated in another part of the factoryThus, material would move long distances and along crossing pathsIf required, material may be taken to a separate building If machine in one department is engaged , the partly finished material awaiting for operation may be taken to storeMachines in each department attend to any product that is taken to them and are therefore general purpose machine

Process Layout in ServicesWomens departmentWomens dressesWomens sportswearShoesCosmetics and jewelryEntry and display areaHousewaresChildrens departmentMens departmentManufacturing Process Layout

13Advantages :Greater flexibility in operationReduced investment on machines Scope for expansionBetter utilization of men and machinesEasy to handle breakdown of machinesGreater incentive to individual worker to increase performance Disadvantages : Inefficiency as jobs or customers do not flow to the system in an orderly mannerTime required is more as each new arrival require a new setup differently for processing requirements and more work in progress has to travel from place to place Difficulty in movement of materialsMore floor space

Product layout Known as assembly lines Arrangement of activities and machines in a line according to the sequence of operations that need to be performed to assemble a particular productMaterials are fed into the first machine and finished products come out Partly finished goods travel automatically throughout processes Each product has its own line specifically designed to meet its requirements Conveyors are most common material handling equipment Product layouts are suitable for mass production or repetitive operations in which demand is stable and volume is highA Product LayoutInOut16Advantages :Efficiency increases Reduction in material handling costEconomy in manufacturing timeLayout facilitates better controlWork in progress is reduced and investment on that can be minimized

Disadvantages :Inflexibility ExpensiveDifficulty in supervision Any breakdown can disturb the whole system

Description

Type of process

Product

DemandVolumeEquipmentSequential arrangement of activitiesContinuous, mass production, mainly assembly

Standardized, made to stock StableHighSpecial purposeProcessFunctional grouping of activitiesIntermittent, job shop, batch production, mainly fabricationVaried, made to order FluctuatingLowGeneral purposeProductComparison of Product and Process LayoutsWorkersInventory

Storage spaceMaterial handlingLayout decisionGoal

AdvantageLimited skillsLow in-process, high finished goodsSmallFixed path (conveyor)Line balancingEqualize work at each stationEfficiencyProcessVaried skillsHigh in-process, low finished goodsLargeVariable path (forklift)Machine locationMinimize material handling costFlexibilityProductComparison of Product and Process LayoutsFixed-Position LayoutsTypical of projects Fragile, bulky, heavy itemsEquipment, workers & materials brought to siteLow equipment utilizationHighly skilled laborTypically low fixed costOften high variable costs7-21

7-22

ForkliftDesigning Process LayoutsGoal: minimize material handling costsBlock Diagrammingminimize nonadjacent loads use when quantitative data is availableRelationship Diagrammingbased on location preference between areasuse when quantitative data is not availableBlock DiagrammingUnit loadquantity in which material is normally movedNonadjacent loaddistance farther than the next blockStepscalculate composite (two way) movementsdevelop trial layouts minimizing number of nonadjacent loadsBlock Diagramming: ExampleDepartment12345Load Summary ChartFROM/TODEPARTMENT1100502 20050360 40504100 60550 12345Block Diagramming: Example2 3 200 loads2 4 150 loads1 3 110 loads1 2 100 loads4 5 60 loads3 5 50 loads2 5 50 loads3 4 40 loads1 4 0 loads1 5 0 loads1234510020015050506040110Grid 1Nonadjacent Loads 110+40=150Block Diagramming: Example2 3 200 loads2 4 150 loads1 3 110 loads1 2 100 loads4 5 60 loads3 5 50 loads2 5 50 loads3 4 40 loads1 4 0 loads1 5 0 loads1234510020015050506040110Grid 2Nonadjacent Loads: 0Relationship DiagrammingSchematic diagram that uses weighted lines to denote location preferenceMuthers gridformat for displaying manager preferences for department locations28ProductionOfficesStockroomShipping and receivingLocker roomToolroomAAA OOOOO UU U UEX IA Absolutely necessaryE Especially importantI ImportantO OkayU UnimportantX UndesirableRelationship Diagramming29(a) Relationship diagram of original layoutKey:AEIOUXOfficesStockroomLocker roomToolroomShipping and receivingProductionRelationship Diagramming(b) Relationship diagram of revised layoutRelationship DiagrammingOfficesStockroomLocker roomToolroomShipping and receivingProductionKey:AEIOUX31Computerized Layout SolutionsCRAFTComputerized Relative Allocation of Facilities TechniqueCORELAPComputerized Relationship Layout PlanningPROMODEL and EXTENDvisual feedbackallow user to quickly test a variety of scenariosThree-D modeling and CAD integrated layout analysisavailable in VisFactory and similar softwareTypes of Store Layouts

Designing Service LayoutsMust be both attractive and functionalFree flow layoutsencourage browsing, increase impulse purchasing, are flexible and visually appealingGrid layoutsencourage customer familiarity, are low cost, easy to clean and secure, and good for repeat customersLoop and Spine layoutsboth increase customer sightlines and exposure to products, while encouraging customer to circulate through the entire storeHybrid or combined layout A combination of the product and process layout It is possible to have both types of layout in an efficiently combined form if the products manufactured are somewhat similar and not complex

Cellular LayoutsCellular layouts: group dissimilar machines into work centers (called cells) that process families of parts with similar shapes or processing requirements

Identify families of parts with similar flow pathsGroup machines into cells based on part familiesArrange cells so material movement is minimizedLocate large shared machines at point of useParts Families

A family of similar partsA family of related grocery items37Original Process LayoutCABRaw materialsAssembly12345678910111238Part Routing Matrix MachinesParts123456789101112

AxxxxxBxxxxCxxxDxxxxxExxxFxxxGxxxxHxxxFigure 5.839Revised Cellular Layout369Assembly124810571112A B CRaw materialsCell 1Cell 2Cell 340Reordered Routing Matrix MachinesParts124810369571112

AxxxxxDxxxxxFxxxCxxxGxxxxBxxxxHxxxExxx41Cellular LayoutsAdvantagesReduced material handling and transit timeReduced setup timeReduced work-in- process inventoryBetter use of human resourcesEasier to controlEasier to automateDisadvantagesInadequate part familiesPoorly balanced cellsExpanded training and scheduling of workersIncreased capital investment42Flexible Manufacturing Systems (FMS)Consists of programmable machine tools automated tool changingautomated material handling systemcontrolled by computer networkCombines flexibility with efficiencyLayouts differ based onvariety of parts the system can processsize of parts processedaverage processing time required for part completionDesigning Product LayoutsObjectiveBalance the assembly lineLine balancingtries to equalize the amount of work at each workstationPrecedence requirementsphysical restrictions on the order in which operations are performedCycle timemaximum amount of time a product is allowed to spend at each workstation

Line Balancing ProcedureDraw and label a precedence diagramCalculate desired cycle time required for lineCalculate theoretical minimum number of workstationsCalculate efficiency of line

Cycle Time ExampleCd = production time availabledesired units of outputCd = (8 hours x 60 minutes / hour)(120 units)Cd = = 4 minutes480120Flow Time vs Cycle TimeCycle time = max time spent at any station Flow time = time to complete all stations1234 minutes4 minutes4 minutesFlow time = 4 + 4 + 4 = 12 minutesCycle time = max (4, 4, 4) = 4 minutesEfficiency of Line and Balance Delayji = 1tinCaE =ji = 1tiCdN =EfficiencyMin# of workstationswhereti= completion time for element ij= number of work elementsn= actual number of workstationsCa= actual cycle timeCd= desired cycle timeBalance delaytotal idle time of line = nCa -ji = 1tiLine Balancing0.10.20.40.3DBCAWork ElementPrecedenceTime (Min)

APress out sheet of fruit0.1BCut into stripsA0.2COutline fun shapesA0.4DRoll up and packageB, C0.3Line BalancingCd = = = 0.4 minute40 hours x 60 minutes / hour6,000 units24006000N = = = 2.5 3 workstations1.00.40.1 + 0.2 + 0.3 + 0.40.4Work ElementPrecedenceTime (Min)

APress out sheet of fruit0.1BCut into stripsA0.2COutline fun shapesA0.4DRoll up and packageB, C0.350Line BalancingCd = 0.4N = 2.50.10.20.40.3DBCARemainingRemainingWorkstationElementTimeElements1A0.3B, CB0.1C, D2C0.0D3D0.1noneLine BalancingA, BCDWork station 1Work station 2Work station 30.3 minute0.4 minute0.3 minuteCd = 0.4N = 2.5E = = = 0.833 = 83.3%0.1 + 0.2 + 0.3 + 0.43(0.4)1.01.2