Used in transportation moDELLing to minimise the cost. The steps are
- Select any unused square to evaluate
- Begin at this square. Trace a closed path back to the original square via squares that are currently being used (only horizontal or vertical moves allowed)
- Place + in unused square; alternate - and + on each corner square of the closed path
- Calculate improvement index: add together the unit cost figures found in each square containing a +ve; subtract the unit cost figure in each square containing a -ve.
- Repeat steps 1-4 for each unused square
if the index total is -ve that means you have saved money.
