Item Amount Back calculation

Item Amount Back calculation

A common problem expressed by users of ERPNext (and many other ERP software users) is the calculation precision amounts.

ERP software of the company entering a purchase invoice for record keeping often have different precision than the ERP software of the company which issued the invoice.

To add another level of complexity, when printing this data on a paper invoice, the price, quantity and even the amount of each line item might be rounded, rendering the original calculation data unavailable.

This creates a seemingly trivial problem that has found solutions such as adding or deducting a rounding amount per invoice to make it reflect the real number printed on the invoice. When this happens at the invoice level, it provides a “band-aid” which allows the workflow of entering several purchase invoices to continue, but the line items are inaccurate.

This adds time required to enter each invoice, since the user must manually calculate beyond two decimal points the amount to be discounted or added.

And the problem remains that each line item (quantity x rate = amount) is imprecisely entered.

This problem frequently happens with fuel purchases for which we track inventory.

As a solution for our users entering data we decided to incorporate a solution into our workflow, such that they are only required to enter: Item code/name Quantity UOM Rate Amount or line printed on Invoice

Our solution requires float precision of at least 6 and Currency precision of at least 3 (Setup>System Settings>Date and Number Format)

The user creates a new purchase invoice. User enters supplier and date, and any other task specific fields desired. When entering items in the Items table, user enters the item code or name and confirms it either by clicking on the auto-dropdown suggestion or pressing ENTER. Then user tabs to the Quantity field and enters the quantity shown on the Invoice, confirmong it with ENTER. User tabs to Rate, and enters the Rate (if different from pre-loaded rate) If changed, user presses ENTER. At this point, the amount of the line is recalculated and added to the invoice total. If invoice amount is 200.00, but ERPNext is showing an amount of 200.013, this is where this tool will come in handy.

The user now presses the arrow at the right of the line to open the dialog, scrolls down to the “Amount” field, and right below it is the field for desired amount entry. User enters the following: “200.00” and presses enter. At this point it triggers the re-calculation of the quantity, by iterating up to 10,000 times a multiplication of a different quantity amount and rate, such that it equals the desired “200.00” amount. To be clear, this is estimated with up to 3 decimal points of precision. When a result has been found it automatically places the value in the quantity field. At this point user can continue entering items.

The entire workflow from initial item selection, quantity and rate entry, opening the dialog, scrolling down with arrow or mouse, entering desired amount and pressing enter, until leaving the dialog in preparation for the next item entry, takes an average ERPNext user about 30 seconds.

Compared to our previous methods the same exact invoice used to take 2 minutes to calculate by hand.

A short video will be added soon to clarify this process