SCM 2160 – Formula Sheet – Midterm 2

Inventory Management
EOQ EOQ = (2DS/H)½
TC = S(D/Q) + H(Q/2)
R = d L
Safety stock Q system: R = d L + safety stock P system: Target Inv. = d (P + L) + safety stock
Q = Target Inv. – On-hand Inv.
Forecasting
Naive Ft+1 = Dt Simple Moving Avg. Ft+1 = (Dt + Dt–1 + ! + Dt–(N–1)) /
N
Weighted MA Ft+1 = WtDt + Wt–1Dt–1 + ! + Wt–(N–
1)Dt–(N–1)
Exp. Smoothing Ft+1 = aDt + (1 – a)Ft
MAD = S½Et½ / N MSE = S Et2/ N
MAPD = S½Et ½/ Dt / N CFE = S Et