Manufacturing planning & control (mpc) system
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Transcript of Manufacturing planning & control (mpc) system
Manufacturing Planning & Control System Major Tasks
restate business objectives in operations management terms
ensure feasibility of plans identify gaps in current resources help formulate connective action-Suppliers
prioritize activities - scheduling facilitate feedback
Keys to MPCManufacturing Planning and Control
System
A complete, current and accurate database one set of records high emphasis on data accuracy quick correction of error in db accessible to all who need data
System discipline Transparent logic
Production Plan First step in the planning process One of three high level plans
Business Plan Sales Plan Production Plan
differences between sales plan and production plan is the inventory plan
Long term perspective Stated in aggregate units
Issues Considered Capacity management
level chase mixed
Requires coordination with marketing
Demand management
Definition: document that defines the specific goods that specific shops will produce in definite quantities at definite times over a short-term horizon in accordance with the aggregate plan
The MPS represents an agreement between marketing and manufacturing
Master Production Schedule
Master Production Schedule
A detailed disaggregation of production plan Time-phased statement of how over the
planning horizon resources will be used to meet agreed-to commitments
Tends to be: short time horizon more detailed product information (BoMs) more concern over capacity corporate plan quasi-contract updated regularly
What is the MPS? Plan showing availability Build schedule Stated in BoM terms
MPS Problems Overloaded Front End Loaded Unstable Incomplete Short Horizon Wishlist
Stability in MPS Balance need of OM for stability and marketing for
change. Why is stability important? How introduced?
timing fencing time fences denote different reaction to changes and
willingness to accommodate change recognizes increasing cost of change as we near current
time Different zones
types of changes who approves who bears cost
MPS Principles The MPS must be in concert with the
production plan The MPS must drive the entire
materials management system Include all known requirements in the
preparation of the MPS and the FAX Minimize the number of items needed
to adequately express the MPS and the FAS
MPS – Master Production Schedule Short term
(Aggregate) Production Plan families
BOM – Bill of Material Routing file
Key Terms from Ch. 14
Material Requirements Planning
Brunswick Motors
Applying MRP to InventoryPlanning & Scheduling
MRP and Dependent Demand
Dependent Demand demand that is derived consists of WIP + Raw materials concept of parent/component independent demand in MPS
Problem with Dependent Demand information generated challenge - generating 100% CSL past approach - s,Q new approach - MRP
Prior to MRP Up to 1970s, extensive use of s,Q
models why? Simple to use, limited information
requirements, “optional” Why move to MRP?
problems with s,Q models high levels of inventory high stockouts poor customer services
“Order launch & Expedite”
Why MRP? (2) S,Q ignored BoM information
Item OQ OHA 300 0B (comp) 250 0C 200 0D 250 0
A uses 1 B; B uses 1 C; C uses 1 D
What happens if we receive an order for 50 units of A?
Other Factors Major changes
high cost of inventory increased availability of more
powerful computers decreasing cost of computers
MRP now supported by extensive body of software
MRP Elements Gross Requirements On-Hand Inventory
Allocations Scheduled Receipts Net Requirements Planned Order Releases Time-phasing Parent/Component
MRP Elements Planning factors System nervousness Firm planning Explosion Time buckets
Action bucket Rolling the Schedule Net Change vs. Regenerative MRP
Advantages of MRP Forward looking when planning (visibility) Useful simulator Provides valid, credible priorities
priorities reflect actual needs, not implied needs.
Provides mangers with control over the execution system
Forms basis for building credible, valid formal system
Limitations of MRP only looks at materials, ignores
capacity, shop floor conditions requires user discipline requires accurate information/data requires valid MPS not appropriate for all areas
high volume production projects
Types of MRP Systems MRP Closed Loop MRP MRP II Distribution Requirements Planning DRP II Enterprise Requirement Planning
The Curve 42-50 A 23 37-41 B 37 31-36 C 30 26-30 D 7 >26 F 1
Mean 2.75