The Owner wanted to reduce entry mistakes and improve efficiency for creating invoices. He wanted to continue using Microsoft Excel, and had a small number of big clients. So, a simple solution in Excel was preferable.
I compiled a full product list. I created the application to have dropdown lists for the entry of the products and categories for each line item within the worksheet, the prices would be autofilled on selection.
The Owner can update the product list with new products and prices if desired, and the application will update the dropdown lists instantly.
The objectives were all met with the minimum impact to the Owner's existing workflow!