Formulas and Data Rollup

Hi,

I am in the process of putting together a sheet that logs the amount of production each day.

As a bit of background we are an aggregate manufacturing and contracting business and what i am trying to do is have a sheet that tracks the amount of production of each product per day.

I have created a sheet with all the products listed in columns with other columns for entered by, date etc. This has been rolled up into a webform for easy entry (I am experimenting with an Appsheet app as well)

What I would like to do is rollup the data somewhere in the sheet to show

1) Totals produced forever

2) Totals produced within date ranges

3) Days a product has been produced

for 1) I have tried totalling the data at the top of the sheet which is ok but i tried suming the column but I cannot get this to work because of the other rollup data. Question is there a way to total from say row 15 until the end of the sheet so it will take into account of new entries from the web form?

For 2) Is there a formula that will calculate totals between defined dates the total of each material produced within a month? Again taking into account all cells of a column except say the first 15 (roll up data)

For 3) Is there a formula that will calculate the total days a product has been produced i.e count the number of cells that have a value other than 0 within an entire column? Say if there are 30 entries with 10 showing a value other than 0 the total would show 10. Again taking into account all cells except say the first 15 in the column(roll up data)

I have attached a screenshot to try to show what I am trying to do!

If i can get this to work my intention is to use zapier or linked cells to send this 'total' data to another sheet so I can keep track of when materials need testing as the specifications are based both on amounts and production days.

If there is a better way then please point me in the right direction

Sorry for the longwinded question! And thankyou for your help in advance

Leo