CPIMDSP-Session3StudyNotes.doc

1、Session ThreeInformation Used in the Materials Planning Process- Information used in material planning Differentiate among planning factors, inventory status data, and historical demand and usage data.# Inventory data Planning factors Lot size (order quantity)- The policy can be lot-for-lot to meet

2、the exact quantity needed or a quantity based on EOQ or other factors. Lead time Safety stock Scrap- Material outside of specifications and that is not practical to rework. When a process produces scrap, MRP increases the planned order release amount for the parent item to account for a scrap or yie

3、ld factor. Inventory status data On-hand balance- It includes inventory available for planning at all locations. Allocations- Some of the total inventory on hand may be reserved for or allocated to specific planned ordersthat have been released. Also, allocations may be used to manage expensive item

4、s or those in short supply. Scheduled receipts- A scheduled receipt is an open order. It appears in an MRP grid or record as due in a specific period (time bucket), but the item s release date is not shown because the order occurred before the first period shown in the record.- A scheduled receipt c

5、onsists of two parts: how much; when the item will arrive Historical demand and usage data Item number;Item description; Stock locations;On-hand balances at each stock location; On-order information by due date; Reorder and safety stock information; Financial information;Usage;Unit of measure;Classi

6、fication (ABC);Source code;Lead time- 1 - Explain the relative advantages of meaningful and non-meaningful item number.Advantages of meaningful codesEasier to understand, work with, andrecallEasier recognition of part identity increases organization efficiencyEasier to detect miscode items using siz

7、eor color informationEasier to interpret using hyphens orsymbolsAdvantages of non-meaningful codesShorter codes are faster to input orwriteNumerical codes are easier and faster toinputRandom or sequential numberassignment is better at accommodating the growth of item numbersNon-meaningful codes can

8、be automatically generated by software# Introduction to the MPS Material-dominated vs. Processor-dominated scheduling Material-dominated scheduling is a technique that schedules materials before equipment or capacity. In contrast, processor-dominated scheduling is a technique that schedules equipmen

9、t and capacity first. Master scheduling and MRP are in the material-dominated scheduling category. Goals of master scheduling Balance supply and demand per the production plan Plan efficient use of company resources Determine end-item priorities shown in the MPS Hand off from MPS to MRP, which then

10、establishes and maintains the priorities for components and assemblies Sources of MPS Requirement Sales forecast;Interplant order;Special Engineering needs; Service part requirement; Special promotion; Safety stock change; Anticipation buildup Explain the minimum length of the planning horizon for t

11、he MPS.-The planning horizon is the amount of time the MPS extends to the future. The MPS planning horizon should be at least as long as the cumulative lead time for the item being scheduled.- The planning horizon is usually longer than lead time to facilitate the following:1) Component lot sizing2)

12、 Shop floor and capacity planning3) Scheduling by the suppliers and work centers Bill of materials(see study notes of MPR)- 2 - Characteristics of the material planning progress# Material Planning in different production environments* Not all production environments will require MRP systems. Project

13、 and Engineering-to-Order Environment Characteristics:- Demand is lumpy; product volume is low.- Project are often unique, generally large, and of lengthy duration. Material Planning Process: Project Planning ToolProcess Flow Environment Characteristics:- Demand is stable and continuous; volume is h

14、igh and variety is medium to low.- Production is usually make-to-stock; it is scheduled to meet forecasted demand rather thancustomer orders.- All products have similar routines.- Products tend to be commodities, with exceptions in pharmaceuticals.- Plants are designed for a specific throughput and

15、require specialized equipment. Material Planning Process: MRP with anoptimizer schedulingsoftwareP3-35/ P.G. Lean/JIT Environment Characteristics:- Demand is stable and continuous, and volume is high.- Product variety is low, and products are standard and not complex.- Process is repetitive.- Machin

16、ery and workers in the factory are flexible. Material Planning Process: Forecasting + MRP + PULL + Waste eliminationP3-37/ P.G. MRP Environment Characteristics:- Low volume/ high-variety make-to-order job shop or batch production environments.- Medium-to-high volume/ low-to high variety assemble-to-

17、order repetitive flow environments. * An MRP system is a planning system/ tool that can be used in either a PUSH or PULL system.# MRP Model Inputs and OutputsInputsOutputsPlanning factorsPlanned order release for purchased itemsInventory data (status)Planned order release for manufactured itemsMaste

18、r production scheduleException reports and action messagesBill of materials* Exception report are usually produced as a result of running MRP and include a list of actions that need to be taken.- 3 -* Action messages contain the details of actions, such as: Expedite or de-expedite released ordersPla

19、nned order due for release Cancel order MRP FunctionsIt plans and controls the firm s inventories, establishing what, how much, and when to order.It plans and controls order released to the factory floor and suppliers in order to meet the right due dates, and it keeps due dates valid.It provides acc

20、urate planned-order loading for use by capacity requirements planning and constraint management. Planning process parameters MRP planning horizon should be at least as long as the cumulative lead time of the end item being scheduled. Insufficient planning horizon can have some adverse consequences:- When BOMs are exploded, the impact of the short planning horizon is felt most at the lowes