Chapter 13 Flashcards
Material Requirements Planning (MRP)
activity that determines the ordering of dependent-demand items (components of assembled products).
MRP II
second generation MRP, adds broader scope by linking sales and operations planning, MPS, MRP, CRP, and detailed scheduling
Capacity Requirements Planning (CRP)
uses the MRP shop order releases and operations times and routings to determine the capacity requirements from each work centre.
Dependent Demand
D that depends on the production schedule for the finished goods
What are the 3 MRP Inputs
- Master Production Schedule
- BOM
- Inventory Records
Low-Level Coding
restructuring the BOM so that multiple occurrences of the same component all coincide with lowest level at which said component occurs.
MRP Processing
“explodes” end item requirements specified by the master schedule into time-phased requirements for assemblies, parts, and raw materials using the BOM offset by lead times. Figure 13-8
Gross Requirement
Total expected demand for an item or raw material in a time period (w/o regard to amount on hand).
Scheduled Receipt
open order scheduled to arrive from a vendor or shop floor in the beginning of a period.
Projected on-hand
amount of inventory that us expected to be on hand at beginning of time period. scheduled receipt + any ending inventory expected from last period.
Net requirement
actual amount needed in a time period
Planned-order receipt
quantity planned to be received in the beginning of a period
Planned-order release
Quantity planned to be released in the beginning of a period (planned-order receipt offset by lead time).
Pegging
MRP processing in reverse - identifying immediate parent items that have generated a given set of requirements for an item such as D
2 systems used to update MRP records
- Regenerative
- Net-change
Regenerative System
compiles all changes that occur within the time interval and periodically updates the system.
Net-Change System
production plan is modified to reflect changes as they occur
if some defective purchased parts had to be returned to a vendor, manager can enter this info into the system right when it becomes known.
only changes are exploded through the system, the entire plan is not regenerated.
Regenerative vs Net-Change
Regenerative is better for stable situations. It is disadvantageous, especially in situations where changes are frequent, because there is a time lag between receiving info and updating the system.
MRP System Nervousness
a small change in requirement of an item at the top of the product structure tree can have large effects on items down the tree.
Back-flushing
exploding an end item’s BOM periodically to determine the quantities of the components that must have been used to make the quantity of the item
Primary Reports
- Planned-order schedules
- Order releases
- Changes to scheduled receipts
Secondary Reports
- Performance-control reports
- Planning reports
- Exceptions reports
Planning Bill
when end products only have minor differences (such as colour), they can be combined into an artificial product to simplify planning process
Modular Bill
used to reduce the # of BOMs when a product consists many modules, each with a few options.
