Part I OVERVIEW OF MANUFACTURINGChapters:Manufacturing OperationsManufacturing Models and Metrics

Ch 2 Manufacturing OperationsSections:Manufacturing Industries and ProductsManufacturing OperationsProduction FacilitiesProduct/Production RelationshipsLean Production

Manufacturing Defined - Technological DefinitionApplication of physical and chemical processes to alter the geometry, properties, and/or appearance of a given starting material to make parts or productsManufacturing also includes the joining of multiple parts to make assembled productsAccomplished by a combination of machinery, tools, power, and manual labor.Almost always carried out as a sequence of operations

Manufacturing Defined - Technological DefinitionFig. 2.1.a

Manufacturing Defined - Economic DefinitionTransformation of materials into items of greater value by means of one or more processing and/or assembly operationsManufacturing adds value to the materialExamples:Converting iron ore to steel adds valueTransforming sand into glass adds valueRefining petroleum into plastic adds value

Manufacturing Defined -Economic DefinitionFig. 2.1.b

Classification of IndustriesPrimary industries cultivate and exploit natural resourcesExamples: agriculture, miningSecondary industries convert output of primary industries into productsExamples: manufacturing, power generation, constructionTertiary industries service sectorExamples: banking, education, government, legal services, retail trade, transportation

Manufacturing IndustriesISIC CodeFood, beverages, tobacco 31Textiles, apparel, leather and fur products 32Wood and wood products, cork 33Paper, printing, publishing, bookbinding 34Chemicals, coal, petroleum and their products 35Ceramics, glass, mineral products 36Basic metals, e.g., steel, aluminum 37Fabricated products, e.g., cars, machines, etc. 38Other products, e.g., jewelry, toys 39

More Industry ClassificationsProcess industries, e.g., chemicals, petroleum, basic metals, foods and beverages, power generationContinuous productionBatch productionDiscrete product (and part) industries, e.g., cars, aircraft, appliances, machinery, and their component partsContinuous productionBatch production

Process Industries and Discrete Manufacturing Industries

Manufacturing OperationsThere are certain basic activities that must be carried out in a factory to convert raw materials into finished productsFor discrete products:Processing and assembly operationsMaterial handlingInspection and testingCoordination and controlA processing operation transforms a work material from one state of completion to a more advanced state using energy to alter its shape, properties or appearance to add value to the material.

Fig. 2.3Classification of manufacturing processes

Processing OperationsShaping operationsSolidification processesParticulate processingDeformation processesMaterial removal processesProperty-enhancing operations (heat treatments)Surface processing operationsCleaning and surface treatmentsCoating and thin-film deposition

Assembly OperationsJoining processesWeldingBrazing and solderingAdhesive bondingMechanical assemblyThreaded fasteners (e.g., bolts and nuts, screws)Rivets Interference fits (e.g., press fitting, shrink fits)Other

An assembly operation joins two or more components to create a new entity which is called an assembly, subassembly, etc.

Other Factory OperationsMaterial handling and storageInspection and testingCoordination and control

Material HandlingA means of moving and storing materials between processing and/or assembly operations

Material transportVehicles, e.g., forklift trucks, AGVs, monorailsConveyorsHoists and cranesStorage systemsUnitizing equipmentAutomatic identification and data capture (AIDC)Bar codesRFIDOther AIDC equipment

Time Spent in Material HandlingFig. 2.4

Inspection and TestingInspection examination of the product and its components to determine whether they conform to design specificationsInspection for variables - measuringInspection of attributes gagingTesting observing the product (or part, material, subassembly) during actual operation or under conditions that might occur during operation

Coordination and ControlRegulation of the individual processing and assembly operationsProcess controlQuality controlManagement of plant level activitiesProduction planning and controlQuality control

Production FacilitiesA manufacturing company attempts to organize its facilities in the most efficient way to serve the particular mission of the plantCertain types of plants are recognized as the most appropriate way to organize for a given type of manufacturingThe most appropriate type depends on:Types of products madeProduction quantityProduct variety

Production QuantityNumber of units of a given part or product produced annually by the plantThree quantity ranges:Low production 1 to 100 unitsMedium production 100 to 10,000 unitsHigh production 10,000 to millions of units

Product VarietyRefers to the number of different product or part designs or types produced in the plantInverse relationship between production quantity and product variety in factory operationsProduct variety is more complicated than a numberHard product variety products differ greatlyFew common components in an assemblySoft product variety small differences between productsMany common components in an assembly

Product Variety vs. Production QuantityFig. 2.5

Low Production QuantityJob shop makes low quantities of specialized and customized productsAlso includes production of components for these productsProducts are typically complex (e.g., specialized machinery, prototypes, space capsules)Equipment is general purposePlant layouts:Fixed positionProcess layout

Fixed-Position LayoutFig. 2.6 (a)

Process LayoutFig. 2.6 (b)

Medium Production QuantitiesBatch production A batch of a given product is produced, and then the facility is changed over to produce another productChangeover takes time setup timeTypical layout process layoutHard product varietyCellular manufacturing A mixture of products is made without significant changeover time between productsTypical layout cellular layoutSoft product variety

Cellular LayoutFig. 2.6 (c)

High Production (mass production)Quantity production Equipment is dedicated to the manufacture of one productStandard machines tooled for high production (e.g., stamping presses, molding machines)Typical layout process layoutFlow line production Multiple workstations arranged in sequenceProduct requires multiple processing or assembly stepsProduct layout is most common

Product LayoutFig. 2.6 (d)

Relationships between Plant Layout and Type of Production FacilityFig. 2.7

Product/Production Relationships Total number of product units = Qf = Product varietyHard product variety = differences between productsSoft product variety = differences between models of products Product and part complexityProduct complexity np = number of parts in productPart complexity no = number of operations per part

Factory Operations ModelSimplified for purposes of conceptualization:Total number of product units Qf = PQTotal number of parts produced npf = PQnpTotal number of operations nof = PQnpno

Limitations and Capabilities of a Manufacturing PlantManufacturing capability - the technical and physical limitations of a manufacturing firm and each of its plantsThree dimensions of manufacturing capability:Technological processing capability - the available set of manufacturing processesPhysical size and weight of productProduction capacity (plant capacity) max production quantity that can be made in a given time under assumed operating conditions

Lean ProductionOperating the factory with the minimum possible resources and yet maximizing the amount of work accomplishedResources include workers, equipment, time, space, materialsAlso implies completing products in the minimum possible time and achieving a very high quality level to completely satisfy the customerIn short, lean production means doing more with less, and doing it better

Lean Production and Manufacturing ActivitiesManufacturing activities can be divided into three categories:Value-adding activities - contribute real value to the work unitAuxiliary activities - support the value-adding activities but do not contribute value to the productWasteful activities - do not add value nor do they support the value adding activitiesIf not performed, there would be no adverse effect on the productELIMINATE !

Programs Associated with Lean ProductionJust-in-time delivery of partsWorker involvementContinuous improvementReduced setup timesStop the process when something is wrongError preventionTotal productive maintenance