Deterministic model

Different costs

Ordering/setup cost

Purchasing cost

Holding cost

Shortage cost

EOQ with backorders

= P non-directly served clients that come later

Q* = optimal order quantity

P* = optimal backorder quantity minimizing total cost

EOQ with discounts

1 - Graphically represent the curves TC

2 - Compute for each curve the associated EOQ

3 - Define the total cost curve with jumps

4 - Define the minimum cost for each candidate on each batch size

5 - Compute the total cost TC for each candidate

EOQ - Economic Order Quantity = Wilson's model

Parameters

Variable

Objective function

Properties

ROP - Reordering point

= D*L

Critical level of stock as a warning signal

Ordering costs = O*(D/EOQ)

Holding costs = H*(EOQ/2)

Si Ordering costs = Holding costs => batch size = EOQ

= determine the optimal batch size/order quantity minimizing the total cost TC

Q = order quantity / batch size (unit)

D = demand (unit/time unit)

O = ordering cost (€/order)

H = holding cost (€/unit/time unit)

v = product value (€/unit)

L = lead time (time unit)