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Production Plant Layout (1)Production Plant Layout (1)
• Facility Layout Problem: design problemFacility Layout Problem: design problem– locations of activitieslocations of activities– dimensionsdimensions– configurationsconfigurations
• No overall algorithm existsNo overall algorithm exists
Design problem
Greenfield Location of one new machine
Production Plant Layout (2)Production Plant Layout (2)
• Reasons:Reasons:– new productsnew products– changes in demandchanges in demand– changes in product designchanges in product design– new machines new machines – bottlenecksbottlenecks– too large bufferstoo large buffers– too long transfer timestoo long transfer times
Production Plant Layout (2)Production Plant Layout (2)
DesignDesign
Layout
Product
Logistics Process
Production Plant Layout (3)Production Plant Layout (3)
• Goals (examples):Goals (examples):– minimal material handling costsminimal material handling costs– minimal investmentsminimal investments– minimal throughput timeminimal throughput time– flexibilityflexibility– efficient use of spaceefficient use of space
Production Plant Layout (4)Production Plant Layout (4)
• Restrictions:Restrictions:– legislation on employees working legislation on employees working
conditionsconditions– present building (columns/waterworks)present building (columns/waterworks)
• Methods:Methods:– Immer: The right equipment at the right Immer: The right equipment at the right
place to permit effective processingplace to permit effective processing– Apple: Short distances and short timesApple: Short distances and short times
Goals Production Plant LayoutGoals Production Plant Layout
• Plan for the preferred situation in the Plan for the preferred situation in the futurefuture
• Layout must support objectives of the facilityLayout must support objectives of the facility
• No accurate data No accurate data layout must be flexible layout must be flexible
production rateproduction rate– types and number of machinestypes and number of machines– continuous/intermittentcontinuous/intermittent– layout layout schedule schedule
1/2 - Flow and Activity Analysis1/2 - Flow and Activity Analysis
• Flow analysis:Flow analysis:– Types of flow patternsTypes of flow patterns– Types of layoutTypes of layout
• Production line according to the Production line according to the processing sequence of the productprocessing sequence of the product
• High volume productionHigh volume production
• Short distancesShort distances
Process layout (Job shop)Process layout (Job shop)
• All machines performing a particular All machines performing a particular process are grouped together in a process are grouped together in a processing departmentprocessing department
• Low production volumesLow production volumes
• Rapid changes in the product mixRapid changes in the product mix
• High interdepartmental flowHigh interdepartmental flow
Group layoutGroup layout
• Compromise between product layout Compromise between product layout and process layoutand process layout
• Product layouts for product families Product layouts for product families cells (cellular layout)cells (cellular layout)
• Group technologyGroup technology
Production volume and product variety Production volume and product variety determines type of layoutdetermines type of layout
group layout process layout
product variety
production volume
product layout
Layout determinesLayout determines
• material handlingmaterial handling
• utilization of space, equipment and utilization of space, equipment and personnel (table 2.2)personnel (table 2.2)
Flow analysis techniquesFlow analysis techniques
• Flow process charts Flow process charts product layout product layout
• From-to-chart From-to-chart process layouts process layouts
• Spatial picture of the relationships Spatial picture of the relationships between departmentsbetween departments
• Constructing a relation diagram often Constructing a relation diagram often requires compromises. requires compromises. What is closeness? 10 or 50 meters?What is closeness? 10 or 50 meters?
• See figure 2.25See figure 2.25
Relationship diagram (2)Relationship diagram (2)
PremisePremise:: geographic geographic proximityproximity reflects the reflects therelationshipsrelationships
Sometimes other solutions:Sometimes other solutions:– e.g. X-rating because of noise e.g. X-rating because of noise acoustical acoustical
panels instead of distance separationpanels instead of distance separation– e.g. A rating because of communication e.g. A rating because of communication
requirement requirement computer network instead of proximitycomputer network instead of proximity
Graph theory based approachGraph theory based approach
• close close adjacent adjacent
• department-nodedepartment-node
• adjacent-edgeadjacent-edge
• requirement: graph is planar requirement: graph is planar (no intersections)(no intersections)
• region-faceregion-face
• adjacent faces: share a common edgeadjacent faces: share a common edge
graphgraph
Primal graph Primal graph dual graph dual graph
• Place a node in each face Place a node in each face
• Two faces which share an edge – join Two faces which share an edge – join the dual nodes by an edgethe dual nodes by an edge
• Faces dual graph correspond to the Faces dual graph correspond to the departments in primal graph departments in primal graph block layout (plan) e.g. figure 2.39block layout (plan) e.g. figure 2.39
• Limitations to the use of graph theory: Limitations to the use of graph theory: it may be an aid to the layout designerit may be an aid to the layout designer
CORELAPCORELAP
• Construction “algorithm” Construction “algorithm”
• Adjacency!Adjacency!
• Total closeness rating = sum of Total closeness rating = sum of absolute values for the relationships absolute values for the relationships with a particular department.with a particular department.
jiji rTCR
CORELAP - stepsCORELAP - steps
1.1. sequence of placements of sequence of placements of departmentsdepartments
2.2. location of departmentslocation of departments
CORELAP – step 1CORELAP – step 1
• First department: First department:
• Second department: Second department: – X-relation X-relation “last placed department” “last placed department”– A-relation with first. If noneA-relation with first. If none E-relation E-relation
with first, etceterawith first, etcetera
iiTCRmax
CORELAP – step 2CORELAP – step 2
• Weighted placement valueWeighted placement value
1st
8
1
2 3
7 6
5
4
2nd
4 - Space requirements4 - Space requirements
• Building geometry or building site Building geometry or building site space availablespace available
• Desired production rate, distinguish:Desired production rate, distinguish:– Engineer to order (ETO)Engineer to order (ETO)– Production to order (PTO)Production to order (PTO)– Production to stock (PTS)Production to stock (PTS)
• TC(m) = cost per unit produced as a function of mTC(m) = cost per unit produced as a function of m• CC11 = cost per operator-hour = cost per operator-hour• CC22 = cost per machine-hour = cost per machine-hour
• Compare TC(n) and TC(n+1) for n < n’ < n+1Compare TC(n) and TC(n+1) for n < n’ < n+1
Designing the layout (1)Designing the layout (1)
• Search phaseSearch phase• Alternative layoutsAlternative layouts• Design process includesDesign process includes
• Relationship diagram + space Relationship diagram + space
space relationship diagram space relationship diagram
(see fig 2.56)(see fig 2.56)
• Different shapesDifferent shapes
9 – Layout alternatives9 – Layout alternatives
• Alternative layouts by shifting the Alternative layouts by shifting the departments to other locations departments to other locations
block plan, also shows e.g. columns block plan, also shows e.g. columns and positions of machines and positions of machines (see fig 2.57)(see fig 2.57)
selection
detailed design
detailed design
selectionor
Flexible layoutsFlexible layouts
• Future Future
• Anticipate changesAnticipate changes
• 2 types of expansion: 2 types of expansion: 1.1. sizessizes
2.2. number of activitiesnumber of activities
Material handling systemMaterial handling system
• Design in parallel with layoutDesign in parallel with layout
• PresentationPresentation– CAD templates 2 or 3 dimensionalCAD templates 2 or 3 dimensional– simulationssimulations– ““selling” the layout (+ evaluation)selling” the layout (+ evaluation)
10 Evalution (1)10 Evalution (1)
Selection and implementationSelection and implementation• best layoutbest layout
– cost of installation + operating costcost of installation + operating cost– compare compare futurefuture costs for both the new and the old costs for both the new and the old
layoutlayout
• other considerationsother considerations– selling the layoutselling the layout– assess and reduce resistanceassess and reduce resistance
• anticipate amount of resistance for each alternativeanticipate amount of resistance for each alternative
10 Evalution (2)10 Evalution (2)
• Causes of resistance:Causes of resistance:– inertiainertia– uncertaintyuncertainty– loss of job contentloss of job content– ……
• Unmanned vehicle for in-plant transportation on Unmanned vehicle for in-plant transportation on manufacturing and assembly areasmanufacturing and assembly areas
• Two types of guidanceTwo types of guidance– free rangingfree ranging
• dead reckoning + lasers or transpondersdead reckoning + lasers or transponders
– path restrictedpath restricted• induction wires in the floorinduction wires in the floor
• AGV AGV fork lift truck with RF-communicationfork lift truck with RF-communication
Design and operational control of an Design and operational control of an AGV systemAGV system
• AGV systemAGV system– track layouttrack layout– number of AGVsnumber of AGVs– operational controloperational control
• Single load:Single load: Performance indicators:Performance indicators:- Throughput- Throughput- Throughput times- Throughput times
Operational controlOperational control
• production control production control transportation controltransportation control– flow shopflow shop– job shopjob shop
• centralized controlcentralized control– all tasks are concurrently consideredall tasks are concurrently considered
• or decentralized controlor decentralized control– FEFS: AGV looks for work (suited for tandem configuration)FEFS: AGV looks for work (suited for tandem configuration)
• think-aheadthink-ahead– combine tasks to routescombine tasks to routes
• or no think-aheador no think-ahead
Relations between the issuesRelations between the issues