I have several part numbers that come in and out of my lab for troubleshooting. To appease the inventory control folks I am trying to keep a running total of what is sitting in my lab at the end of each day. There are units that are coming in and going out every day.

Currently I have a TAB with the IN portion which is what is brought in on a day by day basis, then I have a sheet that is OUT which is obviously the parts leaving the area. Then I have the TOTAL IN LAB TAB that is calculating the totals of each part number. That formula looks like this. =(C2+IN!D2)-OUT!D2 which is taking the day before total adding the IN number from today and then subtracting the OUT for the current day. Everything goes well until I try to work out the Monday total, because the other formulas depend on the day before obviously I am given a circular reference to this.

Please help. I am sure it is something simple but it is bugging me.

Manufacturing Association.xlsx