Dear Experts
Simple Scope:
A HUGE tank sucks in X and Y and makes A, B, C, D, E, F that are called Grades. A, B, C, D, E, F needs to be made in some sequence to reduce losses and 'sticky' zones (also called Off-Spec production) EVEN THOUGH the Demand RIGHT NOW exists only for B, D and E. Some sequences are invalid e.g. you cannot make D after E but other way round is possible.
GENERAL OBJECTIVE
Given certain Demand (firm and forecast) of Product Grade(s), DETERMINE the optimum sequence of producing different grades in order to minimize off-spec production.
OTHER OBJECTIVES
The transition time between grades should be as low as possible
Set up and Sequence dependent set up time should be as low as possible
Off spec production volume should be as low as possible
Overall campaign profits (margins) should be as high as possible
Demand (process orders) should also be prioritized.
GENERAL CONSTRAINTS
Available Resource Capacity (in Equalized hours)
Minimum Capacity Utilization factor. e.g. it cannot work below 90% of rated capacity.
Maximum capacity utilization factor e.g. it cannot work above 110% of rated capacity
Minimum allowable lot size per grade for feasible production. Each Grade has a different lot size that has historical motivations.
Maximum quantity of all spec and non-spec grades that the reactor can handle in a campaign that can last for upto 2 months.
You are free to decipher and connect the dots.
Thanks
BS