Module 4 - Section C - Material Planning Requirements Flashcards
Material Requirements Planning (MRP)
-set of techniques that uses bill of material data, inventory data, and master production schedule to calculate requirements for material
-time phased –> makes recommendations to reschedule open orders when due dates and need dates are not in phase
time phased MRP begins with items listed on mPS and determines:
1. quantity of all components and material are required
2. date that components/material are required
-explode bill of material, adjusting for inventory quantities on hand or on order, and offsetting net requirements by appropriate lead times
Bill of Material (BOM)
-listing of all subassemblies, intermediates, parts, and raw materials that go into a parent assembly, showing quantity of each required to make an assembly
-used in conjunction with master production schedule to determine items for which purchase requisitions and production orders must be released
Item Master Record
-typically contains identifying and descriptive data and control values (lead times, lot sizes) and may contain data on inventory status, requirements, planned orders, and costs
-item records are linked by bill-of-material (or product structure) records thus defining bill of material
Parent Item
-item produced from one or more components
Single-Level Bill of Material
-display of components that are directly used in a parent item
-shows only the relationships one level down
Multilevel bill of material
-display of all components directly or indirectly used in a parent, together with quantity required of each component
-if a component is a subassembly
Indented Bill of Material
-form of multilevel bill of material
-exhibits highest-level parents closest to left margin and all components going into these parents are shown indented toward the right
-all subsequent levels of components are indented farther to the right
-if a component is used in more than one parent within a given product structure it will appear more than once under every subassembly in which it is used
Summarized Bill of Material
-form of multilevel bill of material that lists all parts and their quantities required in a given product structure
-unlike indented bill of material, it does not list level of manufacture and lists a component only once for the total quantity used
Phantom Bill of Material
-bill of material coding and structural technique used primarily for transient (non-stocked) subassemblies
-for transient item lead time is set to zero and order quantity to lot-for-lot
-represents an item that is physically built but rarely stocked before being used in the next step or level of manufacturing
-used to simplify complex production orders by reducing number of levels in the BOM
-phantom subassembly is not stocked because it does not exist as an actual component (may be only a drawing of diff. parts that will be used at a igher assembly level)
Parts Requisition
authorization that identifies the item and quantity required to be withdrawn from an inventory
example: an order may be release to factory floor but not picked from storage for several days; during that time the item is still part of inventory balance but it has been allocated and is not available; when pick transaction is processed, the inventory system will reduce the item’s on-hand and allocated balances accordingly
Firm Planned Order
-planned order that can be frozen in quantity and time
-computer is not allowed to change it automatically –> responsibility of planner in charge of item being planned
-technique can aid planners working with MRP systems to respond to material and capacity problems by firming up selected planned orders
-normal method of stating the MPS
Action Message
-output of a system that identifies the need for, and type of action to be taken to correct, a current or potential problem
-examples: release order, reschedule in, reschedule out, and cancel
Rescheduling
-process of changing order or operation due dates, usually as a result of their being out of a phase with production or customer commitments
Bill-of-Material Explosion
-process of determining component identities, quantities per assembly and other parent-component relationship data for a parent item
-explosion may be single level, idented or summarized
Requirements Explosion
-process of calculating the demand for the components of a parent item by multiplying the parent item requirements by the component usage quantity specified in the BOM
