Dispatching Rules

What you have to do:

Make sure that both a problem type and all parameters are defined. Choose Heuristic Algortihms|Dispatching Rules from the menu Algorithms and after editing the options press OK. Dependent on the current problem type, special dispatching rules may also be listed as exact algorithms.

Options:

construct active schedule

Choose an algorithm:

TRUE

At each time a job or machine becomes ready schedule the ready unscheduled operation with highest priority. The resulting schedule is active.

FALSE

To extend a partial schedule, among all unscheduled operations without unscheduled predecessor the one with highest priority is appended to the schedule. The resulting schedule is semiactive, but in general not activ.

Priority

Choose one of the following definitions of priority. The algorithm will schedule the operation

RAND

which is randomly determined,

FCFS

which became ready first,

EDD

with the smallest due date,

LQUE

with smallest difference du date-(processing time + tail),

SPT

with smallest processing time

WSPT

with smallest ratio (processing time / weight)

ECT

which can be completed first

WI

with biggest weight,

LPT

with longest processing time

But...

• If you call a dispatching rule as exact algorithm, normally you cannot choose the priority or rule type. If you want to choose, call Algorithms|Heuristic Algorithms|Dispatching Rules.
• Dispatching rules will not appear in any menue if the current problem type cannot be handled by the implemented algorithm.