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Material Requirements Planning (MRP)
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Material Requirements Planning
• Materials requirements planning (MRP) is a means for determining the number of parts, components, and materials needed to produce a product • MRP provides time scheduling information specifying when each of the materials, parts, and components should be ordered or produced • Dependent demand drives MRP • MRP is a software system
Materials Requirements Planning (MRP)
• Computer based system • Explodes Master Schedule (MPS) into required amounts of raw materials and subassemblies to support MPS • Nets against current orders and inventories to develop production and purchased material ordering schedules
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Evaluation of MRP
• Most beneficial to process-focused systems that have long processing times and complex multistage production steps • Lead times must be reliable • Must freeze MPS for some time before actual production • Difficult to implement
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Objectives of MRP
• Improve customer service • Reduce inventory investment • Improve plant operating efficiency
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Firm orders from known customers
Aggregate product plan
Forecasts of demand from random customers
Engineering design changes
Master production Schedule (MPS)
Inventory transactions
Bill of material file
Material planning (MRP computer program)
Inventory record file
Secondary reports
Primary reports Planned order schedule for inventory and production control Exception reports Planning reports Reports for performance control
©The McGraw-Hill Companies, Inc., 2004
Master Production Schedule (MPS) • Time-phased plan specifying how many and when the firm plans to build each end item
Aggregate Plan Aggregate Plan (Product Groups) (Product Groups)
MPS (Specific End Items)
Terms used in MRP
• • • • • • • • • • Bill of Material File Bucket Capacity Requirement Planning Inventory Status File End Item Lumpy Demand Net