How do you use running totals in a formula??

[PQTIII]

I have 4 different time categories that I filter and get a total(duration) using the formula section of the running total field. I need to use those 4 categories in a utilization formula for each group change. But it keeps coming up blank when I try using just a regular formula using the running total fields. How can I make a formula that will use the running totals to calculate utilization?

 

[lbass]

You need to provide the specifics of your formulas and running total. If your formula comes up blank, it suggests that you might have nulls somewhere. You need to figure out where the nulls are occurring and then use a formula to deal with them.

-LB

 

[PQTIII]

LB

I have 4 time cats:1 =ready,2= down, 3=delay, and 4 =standy by. I used the formula part,(evaluate ( cat = 1) etc,) of the running total to sum up each cat and printed it out in the group footer. All that worked fine. I have totals for each cat. Next I have to use a detail total for the total amount of time for a shift. Then here is my problem: I need to use this formula to get the utilization of a piece of equipment:

(Total time - (Down + STandy by)/ Total time)*100

This is where it's coming up blank.

 

[lbass]

What are your group fields? Do you have a group on shift and then on equipment? Or vice versa? Do you want this calculation at the equipment and/or the shift level? What is the time field and what is its datatype? Is total time the sum of times for those four categories? In other words, more information is needed...

-LB

 

[PQTIII]

LB
The grouping goes like this;

Equipment
Shift Date
Shift (day or night)
Status (all sub types of time cats)

All time fields are numbers in seconds. Your correct, the total is basically the total of all of the time cats for each shift. A shift is a 12 hour period. I want the calc for each piece of equipment for each shift. I need equipment utilization per shift.

PT

 

[lbass]

Create a formula:

(sum({table.time},{table.shift}) - ({#Downtime}+ {#Standby})/sum({table.time},{table.shift}))*100

This assumes that your running totals are reset on change of group (shift), and that you are placing the formula in the group (shift) footer.

I don't see why you would get a "blank" if your running totals are not null. Is {table.time} sometimes null? If so, you need to replace the {table.time} field with a formula:

if isnull({table.time}) then 0
else {table.time}

You would then use this in both the formula above and as the field to summarize in the running totals.

-LB