D annual demand
M maximum inventory level
Q order quantity
K fixed ordering cost
h holding cost per unit per year
p shortage penalty cost per unit per year
n number of orders per year
DDl
lower fuzzy deviation value for demand
DDh
upper fuzzy deviation value for demand
DMl
lower fuzzy deviation value for maximum inventory
DMh
upper fuzzy deviation value for maximum inventory
l learning exponent
i order counter
TCUC crisp total cost function
TCUF fuzzy total cost function without learning
TCUFLi fuzzy total cost function with learning for the ith
order
TCUFL fuzzy total cost function with learning for n orders
Dj
l;1
the first lower fuzzy deviation value for j = D, M in the
planning horizon
Dj
h;1
the first upper fuzzy deviation value for j = D, M in the
planning horizon