Chapter 6: pp 209 to 225; [Chapter 7: Service] Process Planning And Technology Decisions for Manufacturing Operations

Process Strategy l Overall approach to producing goods & services l Defines: capital intensity process flexibility vertical integration customer involvement

Types of Processes l Projects l Job Shop l Batch production - relatively stable demand e.g. heavy equipment, specialty chemicals. l Mass production or Assembly line l Continuous production (flow)

Project Batch (Job shop)Mass Continuous Product Unique Made to order Made to stock Commodity CustomerSinglyFew individualsMass marketMass market DemandInfrequentFluctuatesStableVery stable VolumeVery lowLow to medHighVery high VarietyInfiniteMany, highLowVery low SystemLong-termIntermittentFlow linesProcess industry EquipmentVariedGeneral-purp.Special-purp.Highly automated Type of workContractsFabricationAssemblyMix, treat, refine SkillsExpertsWide rangeLimited rangeEquipment craftspeople monitors AdvantagesCustom workFlexibilityEfficiencyHighly efficient qualitysped, low costlarge capacity Disadv.Non-repeatingCostly, slowCapital invest.Difficult to change ExampleConstructionPrinting, bakeryAutos, TV’sPaint, oil, food

IV. Continuous Flow III. Assembly Line II. Batch I. Job Shop Low Volume One of a Kind Multiple Products, Low Volume Few Major Products, Higher Volume High Volume, High Standard- ization Commercial Printer French Restaurant Heavy Equipment Coffee Shop Automobile Assembly Burger King Sugar Refinery Flexibility (High) Unit Cost (High) Flexibility (Low) Unit Cost (Low) Source: Modified from Robert Hayes and Steven Wheelwright, Restoring Our Competitive Edge: Competing through Manufacturing (New York: John Wiley & Sons, 1984). p Exhibit Product Structure Product Life Cycle Stage Not feasible

Process Planning l Make-or-buy decisions l Process selection l Specific equipment selection l Process plans l Process analysis

Process Planning: Process Selection With Break-Even Analysis c f = fixed cost v = volume c v = variable cost per unit p =price per unit

Solving For Break-Even Volume

Break-Even Example Fixed cost = c f =$2,000 Variable cost = c v = $5 per raft Price = $10 per raft

Break-Even Graph

Choosing Between Two Processes $3v = $8,000 v = 2,667 rafts $2,000 + $5v = $10,000 + $2v Process AProcess B Below 2,667 choose A Above 2,667 choose B

Graphical Solution To Process Selection A B A B

Point Of Indifference l Volume where cost of A = cost of B l Rule for choosing process: Above point of indifference choose process with lowest variable cost Below point of indifference choose process with lowest fixed cost

Process Planning: Make-Or-Buy Decisions 1. Cost 2. Capacity 3. Quality 4. Speed 5. Reliability 6. Expertise

Process Planning: Specific Equipment Selection 1. Purchase cost 2. Operating cost 3. Annual savings 4. Revenue enhancement 5. Replacement analysis 6. Risk and uncertainty 7. Piecemeal analysis

Process Planning: Process Plans - documents used l Engineering drawings (Blueprints) l Bill of material l Assembly diagram l Assembly chart / product structure diagram l Operations process chart l Routing sheet

Bill Of Material (unstructured) No.Part No.Part name Outlet end Handle Switch Electric cord Rear housing Motor mounting plate

Product Structure Diagram Upholstery tool Crevice tool Hand-vac Dusting tool Package Packaged Hand-vac Forward housing assembly Screw & lock washer assembly Rear housing assembly

Operations Process Chart Part nameTable leg Part no.2410 UsageTable Assembly No.437 Oper No.DescriptionDept.MachineTimeTools 10Saw to rough length041 20Plane to size043 30Saw to finished length041 40Measure dimensions051 50Sand052

Process Flowchart Symbols Operations Inspection Transportation Delay Storage D

Process Flowchart Step Operation Transport Inspect Delay Storage Distance (feet) Time (min) Description of process Unload apples from truck Move to inspection station Weigh, inspect, sort Move to storage Wait until needed Move to peeler Apples peeled and cored Soak in water until needed Place in conveyor Move to mixing area Weigh, inspect, sort TotalPage 1 0f ft 20 ft 50 ft 100 ft Date: Analyst: TLR Location: Graves Mountain Process: Apple Sauce

Process Planning: Process Analysis l Continuous improvement basic tool is process flowchart l Reengineering basic tool is process map

Process Reengineering Customer requirements data Strategic directive Goals & specifications for process performance High-level process map Detailed process map Pilot study of new design Full-scale implementation Benchmark data Design principles Key performance measures Baseline analysis Innovative ideas Model validation

High-level Process Map Input Output Performance Goal Subprocess

Design Principles For Reengineering 1. Organize around outcomes, not tasks 2. Capture information once, at the source 3. Centralize resources with info. tech. 4. Link parallel sub-processes 5. Design to do work right the first time 6. Remove complexity 7. Identify information & technology levers

Information Technology in Manufacturing Processes l Management information system (MIS) move large amounts of data l Decision support system (DSS) add decision making support l Expert system recommend decision based on expert knowledge

Decision Support System Information: reports model results what if? analysis Computer system: data processing Data Quantitative techniques PersonnelAccounting ProductionMarketingDistributionOther areas Decisions Management Information System What -if? analysis Management Decision Support System

Artificial Intelligence l Neural networks emulate interconnections in brain l Genetic algorithms based on adaptive capabilities in nature l Fuzzy logic simulate human ability to deal with ambiguity

Advanced Communications l Electronic data interchange (EDI) l Internet l Wireless communications l Teleconferencing & telecommuting l Bar coding –Being replaced by Radio Frequency Identification (RFID) l Virtual reality

Manufacturing Technology l Numerically controlled (NC) machines controlled by punched tape l Computer numerical controlled (CNC) controlled by attached computer l Direct numerical control (DNC) several NC machines controlled by single computer

Automated Material Handling l Conveyors l Automated guided vehicle (AGV) l Automated storage & retrieval system (ASRS)

Flexible Manufacturing Systems (FMS) l Programmable machines l Controlled by common computer network l Combines flexibility with efficiency l Reduces setup & queue times

Flexible Manufacturing System Parts Finished goods LoadUnload Computer control room Terminal Machine Tools Conveyor Pallet

Robotics l Programmable manipulators l Follow specified path l Better than humans with respect to hostile environments long hours consistency

Robot Parts l Controller hardware, software, power source l Manipulator robot arm l End-effector “hand”

Computer Integrated Manufacturing (CIM) l Integration of design, manufacture & delivery via computer technology l CAD - uses software to create & modify designs l CAM - uses programmable automation in manufacturing l CAE - links functional design to CAD form design l CAPP - creates processing instructions for CAM l GT- classifies designs to benefit from prior experience

Components Of CIM CIM Product design Manufacture Process planning Systems management RoboticsFMS NC/CNC/ DNC Cells and centers Automated inspection AGV, ASRS JIT/ kanban DSS/ES/ AI LAN, TOP, satellites TQM Bar codes, EDI MRP GTCAECAD IGES, PDES, DMIS DFM Cellular manufacturing MAP, STEP CAD/CAM CAPP

Adoption Of Technology l Technology Readiness l Need well-designed products & efficient processes l Technology Design l Know what to automate l Technology Selection l Choose the right level l Technology Integration l Have a strategy for incremental automation

Reminder: Process Analysis Measurement l Review process performance metrics -- see Chase: pages 162 to Operation time = setup time + run time 2.Throughput time = average time for a unit to move through the system 3.Throughput Rate = 1/cycle time 4.Efficiency = actual output/standard output 5.Utilization = time activated/time available