Manufacturing Information System. Study notes

Transcription

1 Manufacturing Infrmatin System Study ntes 1.0 Material Requirements Planning (MRP I) Material Requirements Planning (MRP) is sftware based prductin planning and inventry cntrl system used t manage manufacturing prcesses. MRP/ERP Systems were first intrduced by Gerge Plssl and Jseph Orlicky in the late 1960s. Oliver Wight cntributed the evlutin t MRP II, t include mre than the factry prductin and material needs. 1.1 Majr Objectives f the MRP Ensure materials and prducts are available fr prductin and delivery t custmers. Maintain the lwest pssible level f inventry Plan manufacturing activities, delivery schedules and purchasing activities Ability t track material requirements Ability t evaluate capacity requirements Means f allcating prductin time MRP is a tl t deal with these prblems. It prvides answers fr several questins: What items are required? Hw many items are required? When are they required? Where are they required? Figure 1.1 shws blck diagram fr MRP - I

2 Unit I System Manufacturing Infrmatin Fig 1.1 Blck Diagram fr MRP I 1.2 MRP Input, MRP utput and MRP Prcessing MRP Inputs MRP Prcessing MRP Outputs Master schedule Bill f materials Perfrmance- cntrl reprts MRP cmputer prgrams Primary reprts Secndary reprts Changes Order releases Planned-rder schedules Exceptin reprts Planning reprts Inventry recrds Inventry transactin

3 Fig 1.2 Blck Diagram fr MRP Input, Prcessing and MRP utput Intrductin Page 2

4 Unit I Infrmatin System Manufacturing Figure 1.2 shws Blck diagram fr MRP Input, prcessing and MRP utput. Any MRP/ERP sftware have three imprtant parts. There are MRP input, MRP prcessing and MRP utput Master Prductin Schedule: MPS Time-phased plan specifying timing and quantity f prductin fr each end item. MPS cmes frm sales and marketing MPS cvers abut 1-3 mnths int the future Must cver cumulative lead time Cumulative lead time: The sum f the lead times that sequential phases f a prcess require, frm rdering f parts r raw materials t cmpletin f final assembly. Smetimes MPS is capacity filtered; MPS is curtailed after taking the available capacity int accunt Bill f materials (BOM): A listing f all f the raw materials, parts, subassemblies, and assemblies needed t prduce ne unit f a prduct. Prduct structure tree: Visual depictin f the requirements in a bill f materials, where all cmpnents are listed by levels. Figure 1.3 shws Prduct structure mdel fr Engine. Independent and Dependent Demand Independent demand: Demand fr final prducts. Ex : Car Engine Dependent demand: Demand fr the items that are subassemblies r cmpnent parts t be used in prductin f finished gds. Ex : pistn, Cnnecting rd and shaft

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6 Unit I Manufacturing Infrmatin System Independent demand is Dependent demand is certain. uncertai n. Engine Cylinder Shaft Engine Engine Cam shaft Crank shaft Pistn Oil ring Cmpressi n ring Cnnectin g rd Fig 1.3 Prduct Structure Mdel fr Engine Inventry Levels: Mst ften peple d nt use the term prduct structure tree. Instead use BOM t mean the prduct structure tree. Beginning inventry n hand

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8 Unit I Infrmatin System Manufacturing Scheduled receipts Pipeline inventry nt yet received but it is in the prcess f cming t the inventry MRP Prcessing: Grss requirements Ttal expected demand Scheduled receipts Open rders scheduled t arrive Planned n hand Expected inventry n hand at the beginning f each time perid Net requirements Actual amunt needed in each time perid Planned-rder receipts Quantity expected t received at the beginning f the perid Offset by lead time Planned-rder releases Planned amunt t rder in each time perid MRP utput: Planned rders - schedule indicating the amunt and timing f future rders. Order releases - Authrizatin fr the executin f planned rders. Changes - revisins f due dates r rder quantities, r cancellatins f rders.

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10 Unit I System Manufacturing Infrmatin Perfrmance-cntrl reprts, Planning reprts and Expectatin reprts Inventry Status Recrds Each inventry status recrd cntains five items f infrmatin represented as rws in a table. They are as fllws: Grss Requirements ( GR ) ttal demand fr the stck number in the given time perid. Fr cmpnents and raw materials this demand is derived frm all parent prductin plans (Master Prductin Schedule, if parent is a final prduct and/r Planned Order Releases as defined belw, if parent is a cmpnent). Scheduled Receipts ( SR ) smetimes called "pen rders". These are rders that have been placed but nt yet cmpleted/received. Fr a purchased item, the scheduled receipt culd be in ne f several stages: being prcessed by the supplier, being transprted, r being inspected by the purchaser s receiving department. If prductin is making the item inhuse, the rder culd be n the shp flr being prcessed, waiting fr cmpnents, waiting in the queue, r waiting t be mved t the next lcatin. Prjected n Hand ( POH ) an estimate f the amunt f inventry available each week after grss requirements have been satisfied. This is calculated by taking the POH frm the previus week and adding the scheduled rder receipts and the planned rder receipts and then subtracting the grss requirements. Planned Order Receipts ( POR ) the quantity determined t be required fr receipt at the beginning f a time perid. Planning fr receipt f new rders will keep the POH frm drpping belw safety stck.

11 Planned Order Releases ( PORL ) - planned amunt t rder in each time perid. This shuld equal the Planned Order Receipt ffset by the lead-time. This is a SAMPLE (Few pages have been extracted frm the cmplete ntes:-it s meant t shw yu the tpics cvered in the full ntes and as per the curse utline Dwnlad mre at ur websites: T get the cmplete ntes either in sftcpy frm r in Hardcpy (printed & Binded) frm, cntact us n: Call/text/whatsApp / naarcm@gmail.cm inf@naarcm.cm sales@naarcm.cm Get news and updates by liking ur page n facebk and fllw us n Twitter Sample/preview is NOT FOR SALE