Parul Institute of Engineering & TechnologySubject Code : 171903Name Of Subject : Computer Integrated ManufacturingName of Unit : Group TechnologyTopic : Group TechnologyName of Faculty : Prof.D.P.PatelName of Students: (1) Jadav Jaydeep (2) Kanjaria Mihir (3) Umangi Pathak (4) Kedar Thakar

IntroductionGroup Technology is a manufacturing concept/ philosophy in which similar parts are identified and grouped together in parts, groups or families to take advantage of their similarities in design and productionPart Family is a collection of parts which are similar either because of geometric shape and size or because of similar processing steps required in their manufacture. Sub: CIM Topic: Group Technology

Part FamiliesThe parts which are similar in their design characteristics are grouped in a family referred to as design part family.

The parts which are in their manufacturing characteristics are grouped in a family referred to as a manufacturing part family.The characteristics used in classifying parts are referred as Attributes.Part classification and coding is the process of identifying design and/or manufacturing attributes of a part, listing it and assigning a code numberSub: CIM Topic: Group Technology

123Example of three different part familySub: CIM Topic: Group Technology

Part ClassificationPart classification can be termed in three categoriesSystem based on design attributesSystem based on manufacturing attributesSystem based on both design and manufacturing attributesDesign attributesExternal shapeInternal shapeDimensionsTolerancesMaterialPart functionSurface FinishMajor dimensionsMinor dimensionsManufacturing attributeProduction processesOperation sequenceProduction cycle timeMachine toolTools requiredFixtures requiredBatch sizeAnnual productionSurface FinishSub: CIM Topic: Group Technology

Part CodingCoding structure usually adopted in GT is of 3 types

Hierarchial/ monocodes, in which each element of digit interprets and amplifies the information of the preceding symbols

Attribute codes/ polycode / chain-type structure, in which each feature is assigned a specific location and a set of questions is asked about each feature to determine the value of that particular feature digit and each digit is independent of other digits

Hybrid codes / mised mode structure, which is a combination of best features of the previous two codesSub: CIM Topic: Group Technology

OpitzBasic structure of geometrical codes in Opitz systemSub: CIM Topic: Group Technology

Machining cellsWhen machines are arranged to form composite part/parts in form of cell they are termed as machine cells.

Machine cells are formed to have Better flow of materialReduce work in process inventoryReduce material handling Reduce production timeImprove qualitySimplify production schedulingTo reduce setup timesSub: CIM Topic: Group Technology

Machining cellsThere are four common GT Machine cell configurations

Single machine cellGroup machine cell with manual handlingGroup machine cell with semi integrated handlingFlexible manufacturing cellSub: CIM Topic: Group Technology

Machining cells Group machine cell with manual handlingSingle machine cellSub: CIM Topic: Group Technology

Machining cellsGroup machine cell with semi integrated handlingFlexible manufacturing cellSub: CIM Topic: Group Technology

ADVANTAGES OF GTA good coding and classification system provides design engineering with a system that facilitatesEfficient retrieval of similar partsDevelopment of a data base containing effective product design dataStandardization of designsAvoidance of design duplicationForming of part familiesUse of producibilityIncorporation of engineering design changes into the engineering and manufacturing systems

2. A good coding and classification system provides manufacturing with a system that facilitatesDevelopment of computer aided process planning systemRetrieval of process plans for part familiesDevelopment of standard routings for part familiesDevelopment of machining cellsSub: CIM Topic: Group Technology

ADVANTAGES OF GTHelps in development of tooling groups, NC program groups and standard setupsProduction planning and control is simplifiedProduction scheduling is simplifiedIn process inventory is reduced in machine cellsShorter manufacturing through put timesImproved machine utilization due to shorter setup times and better schedulingGives improvised plant layout and hence reduction in material handlingSince worker carries out similar work, worker satisfaction is increaseBetter quality of workManagement is more effective as environment is simplifiedSub: CIM Topic: Group Technology

DISADVANTAGES OF GTInstalling and implementation is very costly as well as time and effort consumingIf communication between design and manufacturing departments is poor then system may not be successfulThere are no fixed methods/ standards of GT. So no common procedure and hence difficult to implementLarge cost may be incurred for rearranging the machinesWithout strong support from top management implementation of GT is difficultSub: CIM Topic: Group Technology