Assistance required - First in first out material tracker

Hi all,

I'm a new forum member and have a I have an interesting problem which I am finding it hard to solve. I've been looking on these forums for quite some time for solutions but have finally been stumped. I have a decent knowledge of excel but still have a great deal to learn. I've got very limited experience with writing macros and haven't done so for 6 years (Uni) so I'm trying to get a solution through excel functions etc. I'll outline the situation below;

I work in an underground mine. I've been asked to come up with a way of tracking the amount and quality (grade) of ore put into an ore pass; a vertical opening filled from the top and removed from the bottom. On a daily basis I need to track what has been put into the pass and what has been taken out. Each movement / batch will have an associated quality (7 data sets) plus the amount. There will be multiple entries per day for both adding and removal of ore and these entries will not necessarily be the same quantity in or out. To explain: adding 100t of A and 30t of B and removing 110t from A then B leaving 20t of B.

I am required to be able to tell another party what has:
A) Gone into the ore pass daily?
B) What has been removed daily?
C) What is currently in the ore pass?

I'm aiming for a "minimal" data entry solution to my problem if possible, time will tell.

My current thoughts on the question would be assign a sequence number to every entry. I could then use the =MIN() function to deal with the earliest entry. I would then need a function which works out where in the sequence we are up to in terms of removal remembering that it has to account for partial removal (which I can't see a way around at this point).

Basically, what I'm after from you is a starting point for the functions I could utilise to complete my problem. Any input into it would be fantastic. Thanks in advance.

Linc

Ps if you are having trouble picturing my problem here is another more common context would be picture a grain bin, filled from the top and removed from the bottom which has had different grain types put in it.