Some 30 years ago--as the original PC was being released. I wrote a program in BASIC that did critical path scheduling for about 30 houses under construction at any one time on a C-64. It took almost all night to run and print the critical path diagrams.
We have become rather wasteful of memory since then.

__________________
1982 300SD " Wotan" ..On the road as of Jan 8, 2007 with Historic Tags