Creating ETA Formulas based on distance/previous delivery time.

[gretchenanderson]

I work in dispatch for a transportation company. My boss would like me to change the formula in the spreadsheet we use to update our customers the time that their deliveries have been made and the ETA to the rest of the deliveries for that day. Currently, I use the formula =B12+45/1440 B12 being the time estimated above each new ETA. however, the 45 minutes is not always accurate because of distance or the delivery taking longer than usual.

I am looking for a plug and play formula that I can lock (if I am off one day and someone else comes in to send out the update) I think an If- then formula that is if D12=nothing than B12+45/1440, and if D12=(time) than D12+45/1440. But I dont know how to actually input that.

Does this make sense? Here is a picture of the spreadsheet I have created and have been using so far.

 

[MrSyyr]

=if(D12="",B12,D12)+45/1440
is this what you want?

You could use old delivery data to improve the 45 minute estimates too.