MRP, CRP, and ERP

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MRP, CRP, and ERP

• Bills of Materials
• The MRP Record
• The MRP Explosion
• Vertical Linkage of MRP Records
• Validating the Mps
• Capacity Requirements Planning

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ERP
ENTERPRISE RESOURCE PLANNING
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CORE MRP II
MANUFACTURING RESOURCE PLANNING
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THE ORIGINAL MRP (Material Requirements Planning)

• In the beginning (pre-1970's)
• There were no computers
• Material planning was done independently for each
  component
• Then there were computers
• And MRP (I) became possible
• Then there were faster computers
• And MRP II became possible
• Then there were even faster computers
• And ERP became possible

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BILLS OF MATERIALS

• BOM's show how parts are combined to create
  product
• Representation may be graphical or indented
  text
• X
• A
• B (2)
• A
•  Y
• A

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THE MRP RECORD

• Objective is to determine future purchasing or
  production schedule for a component part
• Gross Requirements demand for part
• Scheduled Receipts planned completion times for
  batches of parts which have been already ordered

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THE MRP RECORD

• Objective is to determine future purchasing or
  production schedule for a component part

• Objective is to determine future purchasing or
  production schedule for a component part
• Gross Requirements demand for part
• Scheduled Receipts planned completion times for
  batches of parts which have been already ordered

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THE MRP RECORD

• Objective is to determine future purchasing or
  production schedule for a component part

• Objective is to determine future purchasing or
  production schedule for a component part
• Gross Requirements demand for part
• Scheduled Receipts planned completion times for
  batches of parts which have been already ordered

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THE MRP RECORD

• Objective is to determine future purchasing or
  production schedule for a component part

• Objective is to determine future purchasing or
  production schedule for a component part
• Gross Requirements demand for part
• Scheduled Receipts planned completion times for
  batches of parts which have been already ordered

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THE MRP RECORD

• Objective is to determine future purchasing or
  production schedule for a component part
• Planned Order Receipt planned completion times
  for batches of parts which have not yet been
  ordered
• Planned Order Release planned start times for
  batches of parts which have not yet been ordered

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THE MRP RECORD

• Objective is to determine future purchasing or
  production schedule for a component part
• Planned Order Receipt planned completion times
  for batches of parts which have not yet been
  ordered
• Planned Order Release planned start times for
  batches of parts which have not yet been ordered

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THE MRP RECORD

• During Period 1
• 10 units are disbursed

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THE MRP RECORD

• During Period 1
• 10 units are disbursed
• The scheduled receipt is completed

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THE MRP RECORD

• During Period 1
• 10 units are disbursed
• The scheduled receipt is completed
• The planned order release is released

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THE MRP RECORD

• During Period 1
• 10 units are disbursed
• The scheduled receipt is completed
• The planned order release is released

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VERTICAL LINKAGE OF MRP RECORDS

• Objective find material plans planned order
  releases for all parts
• Data requirements
• MPS
• BOMs
• Inventory records file
• Gross requirements are ultimately derived from
  MPS
• But in calculations, the gross requirements for a
  part depend only on the planned order releases of
  the parent parts

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LOW-LEVEL CODING

• Determines order of MRP calculations
• Each BOM level is assigned a number
• Products are at level 0
• Each part is assigned the number of the lowest
  level at which it appears in any BOM
• Calculate plans for level 0 first, then level 1,
  etc. . . .

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MRP EXAMPLE

• Start with MPS for products X and Y

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MRP EXAMPLE

• Start with MPS for products X and Y

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MRP EXAMPLE

• Planned order releases for X serve as basis for
  gross requirements for part B

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MRP EXAMPLE

• Part Bs record is then completed

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MRP EXAMPLE

• Part Bs record is then completed

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MRP EXAMPLE

• Part Bs record is then completed

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MRP EXAMPLE

• Part Bs record is then completed

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MRP EXAMPLE

• Part Bs record is then completed

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MRP EXAMPLE

• Part As gross requirements depend on planned
  order releases for X, Y, and B

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MRP EXAMPLE

• Part As record is then completed

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MRP EXAMPLE

• Part As record is then completed

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MRP EXAMPLE

• Part As record is then completed

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CAPACITY REQUIREMENTS PLANNING

• Should be used as a final check on the mps
• More accurate than RCCP
• May be too expensive for routine "what-if"
  analysis
• Determine incremental run times and setup times
  for each part in each workcenter
• Apply incremental run times and setup times from
  (1) to planned order releases to determine
  capacity requirements per period for each
  workcenter

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THE ROUTING

• The routing for a product or part lists
• Where it is processed
• Resources needed
• Per batch or per setup
• Per unit after workcenter is setup

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan

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CRP

• The routing is applied to the planned order
  releases to obtain the capacity plan