The Process Flow Spectrum Spectrum Overview Intermittent Flow Operations Continuous Flow Operations Repetitive Flow Operations Selection Criteria Applied Management Science for Decision Making, 1e © 2012 Pearson Prentice-Hall, Inc. Philip A. Vaccaro , PhD The Process Spectrum RAW MATERIALS TO FINISHED GOODS PRE-MADE PARTS ASSEMBLED INTO FINISHED GOODS RAW MATERIALS TO FINISHED GOODS Intermittent Flow Operations Worker Paced Line Flow Continuous Flow Operations ( Job Shop ) Batch Flow Machine Paced Line Flow ALL MANUFACTURING AND SERVICE OPERATIONS ARE ENCOMPASSED BY THE PROCESS SPECTRUM (Mass Production) Layout Definitions The placement of: The spatial or physical arrangement of: people equipment materials within an organization machines offices and desks service centers inventories within factories, warehouses, banks, offices, stores, hospitals, etc. Process Flow Structures Affect Layout of the facility Human and material resources Technology decisions Work Methods Productivity Firm’s strategy for competitive advantage Costs Intermittent Flow Operations Called job shop in everyday parlance. Can only occur within process layouts. Their products move very slowly through the system due to material shortages, long set-up times, worker absenteeism, quality control problems, technical difficulties, and so on. Process Layout Schematic ( INTERMITTENT FLOW OPERATIONS ) PRODUCT FINISH Cutting Center Sanding Center Final Inspect Center Drilling Center Assembly Center Painting Center WAIT LINE EXIT PRODUCT START PRODUCT MOVES FROM CENTER TO CENTER , ENCOUNTERING STOP-AND-GO TRAFFIC FROM START TO FINISH Characteristics PROCESS LAYOUT WORK FLOWS NOT STANDARDIZED ONE OR MORE UNITS OF A PARTICULAR BATCH OF PRODUCT MAY NEED TO BE RE-ROUTED THROUGH THE JOB SHOP DUE TO A MACHINE BREAKDOWN, OR SENT BACK TO THE SAME WORK CENTER TWICE DUE TO QUALITY PROBLEMS OR BREAKAGE. LABOR – INTENSIVE OPERATIONS HAND-CRAFTED OR HUMAN-DIRECTED MACHINE OPERATIONS ON THE GOODS BEING PRODUCED. HETEROGENEOUS PRODUCT MIX A LARGE VARIETY OF DIVERSE PRODUCTS ARE CAPABLE OF BEING PRODUCED. Characteristics PROCESS LAYOUT INTERRUPTED PRODUCT FLOW PRODUCT FLOW IS BLOCKED OR DIVERTED BY MACHINE FAILURES, MATERIAL SHORTAGES, CRITICAL WORKER ABSENCES, QUALITY PROBLEMS, OR UNEXPECTED ADDITIONAL PROCESSING TIMES. LOW PRODUCTION VOLUME ONE, TWO, OR A FEW DOZEN UNITS OF THE SAME MAKE, MODEL, MATERIALS, SIZE, AND COLOR ARE PRODUCED AT ONE TIME. NO CLOSE MANAGEMENT SUPERVISION SHOP FOREMAN TELLS WORKERS WHAT TO DO BUT NOT HOW TO DO IT. S/HE SERVES AS A TECHNICAL RESOURCE ON CALL FOR WORKERS, KEEPS THEM SUPPLIED WITH MATERIALS, AND ACTS AS A LIAISON BETWEEN THE WORKERS AND THE CUSTOMERS. Characteristics PROCESS LAYOUT GENERAL PURPOSE EQUIPMENT EQUIPMENT THAT CAN FABRICATE MANY DIFFERENT TYPES OF PRODUCTS BY MERELY CHANGING THE EQUIPMENT SETTINGS OR ATTACHMENTS. THE EQUIPMENT CAN BE EMPLOYED IN A WIDE VARIETY OF ENVIRONMENTS, WHICH IN TURN, MAKES IT RELATIVELY INEXPENSIVE TO PURCHASE. EXAMPLE A CARPENTRY JOB SHOP TABLE SAW CAN MAKE CUTS FOR BOOKCASES, CHAIRS, DESKS, CABINETS, AND TABLES VIA A BLADE CHANGE OR MINOR ADJUSTMENT. Continuous Flow Operations Called mass production in everyday parlance. Can only occur within product layouts. THEIR PRODUCTS MOVE QUICKLY FROM STATION TO STATION ON A SINGLE PRODUCTION LINE THAT SELDOM STOPS. Product Layout Schematic ( CONTINUOUS FLOW OPERATIONS ) Work Stations 1 2 3 4 INPUTS LABOR MATERIALS LIQUIDS Work-in-Process Units Finished Units Assembly Line or Pipeline Characteristics PRODUCT LAYOUT PRODUCT MADE-TO-STOCK IT PRODUCES PRODUCTS THAT ARE DESTINED TO GO TO A WAREHOUSE FOR SUBSEQUENT DISTRIBUTION, OR A RETAILER FOR ROUTINE MERCHANDISE REPLENISHMENT. UNINTERRUPTED PRODUCT FLOW PRODUCTION IS HALTED ONLY BY SCHEDULED MAINTENANCE, ACCIDENTS, STRIKES, DELIVERY DELAYS, OR NATURAL DISASTER. MANY PRODUCTION PLANTS OPERATE 24 HOURS A DAY, 7 DAYS A WEEK. Characteristics PRODUCT LAYOUT HOMOGENEOUS PRODUCT MIX A SINGLE BASIC PRODUCT WITH MINOR VARIATIONS SUCH AS COLOR, OPTION PACKAGES, TRIM, SIZE, AND SO ON. CAPITAL – INTENSIVE OPERATIONS PRODUCTION THAT RELIES PRIMARILY ON MACHINES, ROBOTS, AND COMPUTERS, WITH NOMINAL OR NO HUMAN INTERVENTION. Characteristics PRODUCT LAYOUT DEDICATED OR SPECIAL-PURPOSE EQUIPMENT EQUIPMENT DESIGNED FOR ONE SPECIFIC TASK, AND FREQUENTLY, INDUSTRY-UNIQUE. IT IS EXPENSIVE BECAUSE IT IS PRODUCED IN SMALL LOTS AND USUALLY POSITIONED AT MANY POINTS ALONG THE ASSEMBLY LINE, EXAMPLE SPOT-WELD ROBOTS IN AN AUTOMOBILE PLANT ARE UNIQUE TO THAT INDUSTRY AND POSITIONED EVERY FEW HUNDRED FEET ALONG A ONE-MILE ASSEMBLY LINE. PRICES START AT OVER A HALF-MILLION DOLLARS! Repetitive Flow Operations encompass Intermittent Flow ( Job Shop ) Batch Flow Worker Paced Line Flow Machine Paced Line Flow Continuous Flow ( Mass Production ) A TRANSITION ZONE BETWEEN INTERMITTENT & CONTINUOUS FLOW OPERATIONS Characteristics REPETITIVE FLOW OPERATIONS Assembly of pre-made parts from independent vendors or sister divisions Semi-skilled labor is utilized Limited product menu is produced ( 6 to 12 ) All products “made” on the same assembly line. ( at different times, of course ) Products share similar parts, technology, and processing steps Just-in-time systems are used to control the inventory. PROCESS FLOWS Let’s take a closer look! Process Structure Characteristics Flow Labor Content Flexibility Labor Skill Production Volume Number of Products Capital Investment Variable Cost EACH OF THESE CHANGES AS WE MOVE ACROSS THE SPECTRUM Process Structure Characteristics Intermittent Flow Operations Continuous Flow Operations FLOW FROM A LARGE NUMBER OF POSSIBLE SEQUENCES OF ACTIVITIES TO ONLY ONE POSSIBLE SEQUENCE PRODUCT NUMBER FROM THE CAPABILITY OF PRODUCING MANY DIFFERENT PRODUCTS TO PRODUCING ONLY 1 PRODUCT VARIABLE COST VOLUME FROM A HIGH UNIT COST TO A LOW UNIT COST FROM A QUANTITY OF ONE TO LARGE-SCALE MASS PRODUCTION Process Structure Characteristics Intermittent Flow Operations Continuous Flow Operations LABOR SKILL / CONTENT FLEXIBILITY FROM HIGH SKILL AND CONTENT TO LOW SKILL AND CONTENT PROCESS PERFORMANCE AND COST ARE INDEPENDENT OF CHANGES IN OUTPUT CAPITAL INVESTMENT FROM USING LOW COST GENERAL PURPOSE EQUIPMENT TO HIGH COST DEDICATED EQUIPMENT Project Architecture • FLOW – no flow • VARIABLE COST – very high • FLEXIBILITY – very high • LABOR CONTENT & SKILL – very high • PRODUCTS – unique • VOLUME – one unit • CAPITAL INVESTMENT – very low Project Architecture Comments Resources are brought to the project site as needed. Technically, a project is not a process flow structure, since there is no flow of product. However, it is useful to think of a project as one extreme of the process continuum. Project Architecture Financial Implications Relatively low fixed costs. Relatively high direct labor costs. Relatively high direct materials costs. Low materials handling costs. Job Shop Architecture • FLOW – jumbled flow • VARIABLE COST – high • FLEXIBILITY – high • LABOR CONTENT & SKILL – high • PRODUCTS – many • VOLUME – low • CAPITAL INVESTMENT – low Jumbled Flow ( NO DOMINANT FLOWS THROUGH THE SYSTEM ) Center 1 Center 2 Center 4 Center 3 Center 6 Center 5 Product A Product B Product C Product D Job Shop Architecture Financial Implications Relatively low fixed costs. Relatively high direct labor costs. Relatively high direct materials costs. High material handling costs. Batch Process Architecture • FLOW – disconnected, with • VARIABLE COST – some dominant flows moderate • FLEXIBILITY – moderate • LABOR CONTENT & SKILL – moderate • PRODUCTS – several • VOLUME – moderate • CAPITAL INVESTMENT – moderate Jumbled Flow ( WITH SOME DOMINANT FLOWS ) Center 1 Center 2 Center 4 Center 3 Center 6 Center 5 Product A Product B Product C Product D Potential Islands Of Automation Jumbled Flow ( WITH SOME DOMINANT FLOWS ) Center 1 Center 2 Center 4 Center 3 Center 6 Center 5 Product A Product B Product C Product D Disconnected Flow One flow only but the work centers are separated from one another in TIME and SPACE Center 1 1,000 ft Center 2 800 ft Center 3 1st Floor or Building No. 1 2 miles 2nd Floor or Building No. 2 Center 4 600 ft Center 5 900 ft Center 6 Batch Process Architecture Comments Products are produced in “batches” ( several dozen units at a time ) . More frequently produced products begin to create dominant flows between certain work centers. The sequence of operations subsequently tends to form one or more “production lines”. The sequence(s) of operations, while “in-line”, is/are still disconnected. Assembly Line Architecture WORKER + MACHINE PACED • FLOW – connected line • VARIABLE COST – low • FLEXIBILITY – low • LABOR CONTENT & SKILL – low • PRODUCTS – a few • VOLUME – high • CAPITAL INVESTMENT – high Connected Flow ( All work centers equidistant from one another and synchronized ) 3 Minute Time Interval Between Centers Center 1 Center 2 Center 3 Center 4 Center 5 20 Feet of Distance Between Centers Center 6 Assembly Line Architecture Comments Like a “batch” process, it processes work in a fixed sequence. However, it connects and paces the work via a moving production line. There is now only one production line! Continuous Flow Architecture • FLOW – continuous • FLEXIBILITY – very low • PRODUCTS – one • CAPITAL INVESTMENT – very high • VARIABLE COST - very low • LABOR CONTENT AND SKILL – very low, but with skilled overseers • VOLUME – very high Continuous Flow Very little or no time interval between work stations Very little or no physical separation between work stations Work Station 1 Work Station 2 Work Station 3 Work Station 4 Processing Steps - heating - cooling - drying - mixing Resource inputs - liquids - materials Work-in-Process Finished Product VERY HIGH SPEED PRODUCTION RATE ( process or actual pipeline ) Continuous Flow Architecture Comments Has a fixed pace and sequence of operations. A single product is processed in a continuous flow, rather than in discrete steps. Production output is measured in weight or volume. Continuous Flow Architecture Financial Implications Relatively high fixed costs. Relatively low direct labor costs. Relatively low direct materials costs. The Process Flow Spectrum Project Job Shop Batch Process Assembly Line Continuous Flow Flow None Jumbled Disconnected & Dominant Connected Continuous Flexibility Very High High Moderate Low Very Low Number of Products Unique Many Several Few One Capital Investment Very Low Low Moderate High Very High Variable Cost Very High High Moderate Low Very Low Labor Content Very High High Moderate Low Very Low Labor Skill Very High High Moderate Low Very Low Volume One Unit Low Moderate High Very High Process Selection Criteria Product variety Product volume Local economics Stage in product life cycle The firm’s business strategy + marketing plans A tradeoff between fixed + variable cost The amount of capital that the firm is able or willing to invest Marketing Implications PROCESS CONTINUUM A job shop allows a firm to sell its capabilities A continuous process flow allows a firm to emphasize the product itself A job shop helps a firm follow a differentiation strategy A continuous process flow helps a firm follow a low-cost strategy Economic Implications PROCESS CONTINUUM Labor A BREAK-EVEN ANALYSIS MAY BE PERFORMED TO ASSIST IN THE PROCESS SELECTION A BREAK-EVEN CHART RELATES COST TO LEVELS OF FORECASTED DEMAND Energy Equipment Transportation Product Life Cycle Implications PROCESS CONTINUUM BIRTH MATURITY DECLINE A JOB SHOP MAY BE THE MOST APPROPRIATE IN ORDER TO FILL EARLY DEMAND AND ADJUST TO DESIGN CHANGES HIGH PRODUCTION VOLUMES MAY JUSTIFY AN ASSEMBLY LINE A BATCH PROCESS MAY BE MORE APPROPRIATE AS PRODUCT VOLUME FALLS AND A VARIETY OF SPARE PARTS IS REQUIRED Traditional Process Layout PRODUCTS CONTINUALLY TRAVEL BETWEEN WORK CENTERS Lathe Center Drilling Center Cutting Center Inspection Center Work Cell Layout GROUP TECHNOLOGY - All jobs take the same route through the shop - Machine setups for all jobs are accomplished by merely changing the software menu - Interchangeable product parts or parts that merely have to be reduced or increased in size, also make the work cell layout possible Work Cell Layout REQUIREMENTS Quick set-up times between jobs Reprogrammable robots and other equipment Production of products sharing similar process requirements, parts, materials, shapes, and handling requirements Work Cell Layout Management STORM DOOR & WINDOW FACTORY Shop makes windows of all sizes, metals, wood, vinyl, glass, and colors with the minimum setup times between each order Major Setup Time Between Window & Door Runs Shop makes storm doors of all sizes, metals, wood, vinyl, glass, and colors with the minimum setup times between each order Work Cell Layout Management Setup Time and Setup Cost Setup time is the time to prepare a machine or process for manufacturing an order. It includes time and labor to clean or change tools, molds, or settings. Setup cost is highly correlated with setup time, and also includes the cost of lost productivity, scrappage, and rework. Work Cell Layout Management MAJOR SETUP (CHANGE BETWEEN PRODUCT GROUPS) WINDOWS DOORS O R D E R O R D E R O R D E R O R D E R O R D E R O R D E R 1 2 3 1 2 3 Work Cell Layout Management MINOR SETUP (CHANGE WITHIN A PRODUCT GROUP) WINDOWS WINDOWS O R D E R O R D E R 2 1 The Process Spectrum RAW MATERIALS TO FINISHED GOODS PRE-MADE PARTS ASSEMBLED INTO FINISHED GOODS RAW MATERIALS TO FINISHED GOODS Intermittent Flow Operations Worker Paced Line Flow Continuous Flow Operations ( Job Shop ) Batch Flow Machine Paced Line Flow ALL MANUFACTURING AND SERVICE OPERATIONS ARE ENCOMPASSED BY THE PROCESS SPECTRUM (Mass Production) The Process Flow Spectrum Project Job Shop Batch Process Assembly Line Continuous Flow Flow None Jumbled Disconnected & Dominant Connected Continuous Flexibility Very High High Moderate Low Very Low Number of Products Unique Many Several Few One Capital Investment Very Low Low Moderate High Very High Variable Cost Very High High Moderate Low Very Low Labor Content Very High High Moderate Low Very Low Labor Skill Very High High Moderate Low Very Low Volume One Unit Low Moderate High Very High Intermittent Flow Operations MANUFACTURING Job Shop Batch Flow ORIGINAL ART WORK LIMITED EDITION ART TOOL & DIE SHOP CUSTOM JEWELRY HEIRLOOM FURNITURE YACHT SUPER COMPUTER DENTAL CROWNS CUSTOM POOL HEAVY MACHINERY FINE JEWELRY FINE FURNITURE ROBOTICS SUITS AMBULANCES TEXTBOOKS Repetitive Flow Operations MANUFACTURING Worker-Paced Line Flow Machine-Paced Line Flow CAMERA ASSEMBLY APPLIANCE ASSEMBLY COMPUTER ASSEMBLY AUTOMOBILE ENGINE ASSEMBLY STANDARD OFFICE FURNITURE COMMON HAND TOOLS TOY ASSEMBLY AUTOMOBILE ASSEMBLY NEWSPAPER PUBLISHING BOTTLING PLANT UTENSILS Continuous Flow Operations MANUFACTURING OIL REFINERY CHEMICAL REFINERY PAPER MILL CONCRETE PRODUCTION LIGHT BULB PRODUCTION GLASS PRODUCTION NUT & BOLT PRODUCTION STEEL MILL ELECTRICITY GENERATION Intermittent Flow Operations SERVICE SECTOR Job Shop Batch Flow TUTORING SMALL CLASSES PHYSICIAN’S OFFICE LIMOUSINE SERVICE CHARTER FLIGHTS LAW FIRM PRIVATE DINING FACILITY INDIVIDUAL SELLING GENERAL HOSPITAL TAXI SERVICE LOCAL AIRLINE LAW CLINIC FINE DINING RESTAURANT BOUTIQUE Repetitive Flow Operations SERVICE SECTOR Worker-Paced Line Flow Machine-Paced Line Flow LECTURE HALL TEACHING DISTANCE LEARNING HERNIA SURGERY CLINIC BUS SERVICE SUPERMARKET FAST FOOD RESTAURANT SCHEDULED AIR LINE CARWASH CINEMA MULTIPLEX LAUNDROMAT TANNING SALON AMUSEMENT RIDES Continuous Flow Operations SERVICE SECTOR Continuous Line Flow RADIO - TELEVISION TELEPHONE SERVICE UTILITIES ON-LINE SHOPPING POLICE PROTECTION FIRE PROTECTION NATIONAL DEFENSE EMERGENCY MEDICAL RESPONSE CHECK CLEARING HOUSE AUTOMATED FLAT- MAIL POSTAL FACILITY Classifying Service System Processes WE FOCUS ON….. 1. How much skill and knowledge the worker must bring to the service. 2. The size of the potential customer service group. 3. The level of customer convenience. The Process Spectrum THE END Applied Management Science for Decision Making, 1e © 2012 Pearson Prentice-Hall, Inc. Philip A. Vaccaro , PhD
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