I recommend you to read material on SCM (supply chain management) and SRM (Supplier relations management) both of which have wide acceptance worldwide. What you are doing is just a small fraction of any of these two I have mentioned. Both concepts talk a complete lifecycle of supply chain. The initiation process, probable supplier, supplier, supply, relations enhancement, quality aspects, rejections, rework, schedules, payments, credit/debit notes etc. – all aspects are covered. Go for any of these two at the earliest and you will gain your market value multifold.