st: Operations Research Bin-packing Problem

[dicke126@umn.edu]

I am trying to develop an initial solution to a bin-packing problem using 
Stata.

I have 2 time blocks (different lengths) over a series of 5 days (10 total 
blocks). Various processes of differing lengths need to be scheduled into 
the time blocks depending on how much time remains available.

As far as I can tell I need to loop over observations one at a time 
completing all the calculations in one observation before moving forward. 
This is because scheduling in one observation changes the available time 
for all remaining observations.

In plain language:
1: schedule process in block if estimated process time < time available for 
block (initially first fit but in future some form of best fit)
2: do not schedule in additional blocks (or replace as some form of missing 
if the process is scheduled in a prior block)
3: reduce time available in block scheduled by estimated processing time 
for all remaining attempts to schedule a process

I can get it to run in such a fashion that:

1: all processes get scheduled in the first block on the first day because 
the time remaining in that block is not adjusted before the comparison 
between available time and estimated processing time occurs.

2: or the first observation works correctly, the available time is 
correctly carried forward to the second (and only the second) observation 
but the comparison and scheduling of additional processes does not occur.

If the code I have created thus far would be useful, I will post.

Thank you in advance for the assistance,
Christopher Dickerson
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