470 likes | 527 Views
Process Choice and Layout Decisions in Manufacturing and Services. Chapter Objectives. Be able to: Describe the five classic types of manufacturing processes. Discuss how different manufacturing and service process choices support different market requirements.
E N D
Process Choice and Layout Decisions in Manufacturing and Services
Chapter Objectives Be able to: • Describe the five classic types of manufacturing processes. • Discuss how different manufacturing and service process choices support different market requirements. • Explain how different processes can be linked together via the supply chain. • Describe the critical role of customization in manufacturing, including the degree and point of customization, and upstream versus downstream activities. • Discuss the three dimensions that differentiate services from one another and explain the different managerial challenges driven by these dimensions. • Create and interpret a service blueprint. • Position a service on a conceptual model and explain the underlying managerial challenges. • Develop a product-based layout using line balancing and calculate basic performance measures for the line. • Develop a functional layout based on total distance traveled.
Manufacturing Processes • Engineering and business perspectives • Classic manufacturing processes • Choosing between classic types • The role of customization
Process A Saddle Machine Shaper Machine Sander A Sander B Inspection Setup Time: 6 hours Time/Seat 1.1 min. Yield Rate: 92% Process B 5-Axis Router ---- Sander A Sander B Inspection Setup Time: 10 min. Time / Seat: 3.5 min. Yield Rate: 99% Solid Wood Seat for a Kitchen Chair:
Classic Engineering Viewpoint • Four Transformation Processes Conversion Fabrication Assembly Testing “Advances in Engineering increase and improve the alternatives available”
Example: Making Windows Conversion Fabrication Assembly • Raw lumber • Molten glass • Frame wood • Window panes Assembled Windows
Business View • What conversion steps must be done? • What are the production volumes like? • How similar are the various products we make (can we standardize)? • If the product is customized, how late in the process does it occur?
Process Types(in order of decreasing volume) • Continuous Flow • Production Line • Batch (High Volume) • Batch (Low Volume) • Job Shop • Project
Continuous Flow • Large production volumes • High level of automation • Basic material passed along, converted as it moves • Usually cannot be broken into discrete units • Usually very high fixed costs, inflexible Oil refinery, fiber formation, public utilities, automotive manufacturing
Production Line High-volume production of standard products or “design window” • Processes arranged by product flow • Often “paced” (‘takt’ time discussed later) • Highly efficient, but not too flexible
Batch I • Somewhere in between job shop and line processes • Moderate volumes, multiple products • Production occurs in “batches” • Can manufacturing, carton makers, advertising mailers, etc.
Batch II Layout is a cross between that found in a line and that found in a job shop: Group Technology
Some Examples of Batch Manufacturing • Numerical control (NC) machines • Automated processing of entire batch • Machining center - multiple NC machines • Flexible manufacturing systems (FMS) • Dedicated to families of parts • NC and automated handling • Group technology • Similar in concept to FMS, but not as much automation
Job Shop • Low volume, one-of-a-kind products • Job shops sell their capability • Highly flexible equipment, skilled workers • Equipment arranged by function
Project • Used when a product is: • one-of-a-kind • too large to be moved • Resources moved to where needed • Equipment, people, etc. are highly flexible • Finite duration, often with deadline Construction projects, equipment installation
Mixing Together the Process Types Hybrid Process Spindles ASSEMBLY LINEfor putting together final product Arms and Legs BATCH for fabricating parts ... Seats
Choosing BetweenClassic Types The product-process matrix Product and process life cycles
Product – Process Matrix Very Poor Fit Very Poor Fit
What is “Customization”? An operations-centric view: “Customization occurs when a customer’s unique requirements directly affect the timing and nature of operations and supply chain activities”
Customization Point Model I Definitions: ETO – engineer to order MTO – make to order ATO – assemble-to-order MTS – make to stock Upstream: before the customization point, “off-line” activities Downstream: after the customization point, “on-line” activities
Off-line Activities Design Buy Materials Fabricate parts Assemble Ship windows On-Line Activities Lead times? Customizability? Price? What type of manufacturing? Sell windows Make-to-Order Windows
An Operations-Centric View Customization becomes relevant to operations and supply chain managers when a customer’s unique requirements directly affect the timing and nature of operations and supply chain activities Job Difficulty Job Routineness Operations and Supply Chain Design Customization
“Mass customization” atJapan’s National Bicycle Co. 2-WEEK LEAD TIME
Law of Variability The earlier customization is introduced in the supply chain, the greater the random variability of the process and the lower its productivity
Services • What makes them distinctive? • High-contact versus low-contact • Front room versus back room • Service Blueprinting
Services . . . • Process and “product” are inseparable • Marketing and sales often tightly integrated • Customer often part of the process • Performance metrics can be harder to define • Nevertheless: • Focus and process choices / trade-offs still apply
Low Contact “off-line” Can locate for efficiency Can smooth out the workload Check clearing, mail sorting High Contact “on-line” Can locate for easy access Flexibility to respond to customers Harder to manage Hospitals, food service Degree of Customer Contact
Classifying Services “Front Room”versus“Back Room” Front room – what the customer can see Managed for flexibility and customer service Customer lobbies, bank teller, receptionist Back room – what the customer does not see Managed for efficiency and productivity Package sorting, car repair, blood test analysis, accounting department
What is it?What is the performance objective? • Restaurant kitchen • Software help desk • Kinko’s copy center • Airline reservations • Jet maintenance
Designing Services • Selecting a service focus • Like manufacturing processes, different services have strengths and weaknesses • Key is to design a service process that meets the needs of targeted customers • The “service package”
Processes Customer actions Onstage activities Backstage activities Support Separations Line of interaction Line of visibility Line of internal interaction Service Blueprinting
Service Blueprint Template(Note similarity to ‘swim lane’ in Chapter 3?)
Community Hospital Public Hospital
Birthing Center Public Hospital
Layout Decision Models • Product-based layout • Usually best for a line operation • Cycle time a primary measure • Functional layout • Usually best for a job shop • Distance between steps a measure • Cellular layout • Usually best for batch processes
Product-Based Layout Line Balancing • Improve ‘Takt’ time: • Use minimum number of workstations • Reduce idle time • Reduce setup time • Reduce unnecessary movement • Identify ‘bottlenecks’
Process Layout Steps • Identify all steps, their relationships, and times required. • Draw a precedence diagram • Determine takt time (time available divided by desired output rate) • Determine minimum number of workstations required (total process time divided by takt time) • Assign tasks to workstations according to precedence and total time for each to not exceed takt time. • Evaluate solution for times per workstation, % idle time, and efficiency delay (100% - % idle time)
Precedence Diagram Example(with workstation task assignments)
Functional Layout Improvement • Minimize the total distance traveled • Determine distances between functional units • Determine numbers of interactions between units • Multiply distances times respective number of interactions • Revise original layout for minimum total distance after first locating functions best for process material flows • Minimize information flow for decisions • Use electronic data interchange (EDI) to allow more flexibility for accomplishing A and B
Case Study in Manufacturing and Service Processes Loganville Window Treatments