Fix-and-Optimize and Variable Neighborhood Search Approaches for Stochastic Multi-Item Capacitated Lot-Sizing Problems

Table 7

Instance generator settings.

Symbol	Definition	Assumptions and settings
Indices and sets:
	Products used to fulfill demand	Set up using clustering algorithm such as K-means clustering and hierarchical clustering after every attribute of products is realized
	Products that are produced by resource	Set up for randomly chosen product
Deterministic parameters:
	Setup cost	See (A.4)
	Unit production cost	See (A.3)
	Unit holding cost	2% of the unit production cost
	Unit capacity	See (A.2)
	Setup time capacity	See (A.1)
	Available capacities	See (A.6)
	Unit backlogging Penalty cost	⩾50 ×
	Overtime cost	See (A.7)
	Demand coefficient	Set for all and .
	Initial inventory	~, with
Random parameters:
	Demand	Normally distributed, stationary across period horizons, but different mean and variation coefficient for each demand: ~ (with values cut-off), with and