1 / 16

PROD 2800 PRODUCTION AND OPERATIONS MANAGEMENT Gestion de la production et des opérations

PROD 2800 PRODUCTION AND OPERATIONS MANAGEMENT Gestion de la production et des opérations. Per AGRELL agrell@poms.ucl.ac.be Lecture 5 Inventory Control. Outline. Key issues Order policies Fixed order quantity EOQ Q-model Variable-time period model (r,Q) Fixed-time period model

radwan
Download Presentation

PROD 2800 PRODUCTION AND OPERATIONS MANAGEMENT Gestion de la production et des opérations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PROD 2800PRODUCTION AND OPERATIONS MANAGEMENTGestion de la production et des opérations Per AGRELL agrell@poms.ucl.ac.be Lecture 5 Inventory Control

  2. Outline • Key issues • Order policies • Fixed order quantity EOQ • Q-model • Variable-time period model (r,Q) • Fixed-time period model • P-model (s,S) PROD 2800

  3. Key issues • 1. Which policy? • 2. When to order? • 3. How much to order?

  4. Inventory Costs • Holding (or carrying) costs. • Costs for storage, handling, insurance, etc. • Setup (or production change) costs. • Costs for arranging specific equipment setups, etc. • Ordering costs. • Costs of someone placing an order, etc. • Shortage costs. • Costs of canceling an order, etc.

  5. Reorder Point System (r,Q) Q r L PROD 2800

  6. Fixed-Time Period Model (S,T) • Review every T periods • Inventory position (IP) = On-hand + on-order - backlog • Order up to level S if IP < s PROD 2800

  7. Fixed-Time Period System (S,T) S s T 3T 2T PROD 2800

  8. Stochastic Demand (S,T) S s T 2T 3T PROD 2800

  9. Safety Stocks PROD 2800

  10. Safety Stock Factors • z P(no stockout) P(stockout) • 0.00 50% 50% • 1.00 84% 16% • 1.64 95% 5% • 1.96 97.5% 2.5% • 2.32 99% 1% PROD 2800

  11. Safety Stocks in (S,T) • S = D(T+L) + zsT+L • = Expected demand over T+L + Safety stock • Order = S – IP PROD 2800

  12. Demand Variability PROD 2800

  13. ABC Classification Share of inventory value A-items B-items C-items Share of inventory records PROD 2800

  14. Adapted Systems • A-items • Individual forecasts • Fixed Order Quantity systems (often) • B-items • Fixed-Time Period systems • Regular follow-up • C-items • Simple rules • Two-bin systems PROD 2800

  15. Reorder one bin Full Empty Two-Bin Systems PROD 2800

  16. Summary • ABC classification • Systems • Fixed quantity, variable time • Fixed time, variable quantity • Safety stock calculations PROD 2800

More Related