Using Metaheuristic and Fuzzy System for the Optimization of Material Pull in a Push-Pull Flow Logistics Network

Table 2

Applied notations in the problem.

Notation	Description
𝜇𝑢=1/𝛽𝑒	Mean value of distribution
𝜎	Standard deviation
𝑋	Random variable
𝑃	Product type, 𝑝=1⋯𝑃; 𝑃=3
𝑇	Time, 𝑡=0⋯𝑇; 𝑇=80×24 hours
ALTPT𝑝	Average local throughput time (in OEM at 𝑇)
AGTPT𝑝	Average global throughput time at 𝑇
TD𝑝	Total delivery of product 𝑝 at time 𝑇
𝜇𝐴	Membership value of fuzzy set 𝐴
Lsize	Capacity of a pallet [1 10]
𝑒	Upper bound of the fuzzy number 𝜇
WIP𝑝	Maximum OEM inventory
𝜑,𝛿	Importance weights; may be chosen arbitrarily by decision-maker
𝑓𝑖	Fitness value of chromosome 𝑖
Pr𝑖	Selection probability value of chromosome 𝑖
Te	Current temperature in SA
Temin	The least temperature in SA
𝑐	The cycle number in the loop of SA
𝐴	Fuzzy set
NPallet	Number of pallets in system [10 60]
𝑏	Lower bound of the fuzzy number 𝜇