Pending purchase items in Material request or Purchase order

I am finding the best practice for Pending purchase item,See the scenario as below

  • Item A,B,C came from the same supplier.
  • For now Auto reorder system generate material request for item A due to item A reach reordering level.
  • Anyway I cannot do the purchasing no because I need to wait item B and C reach the reordering level too. To make shipment cost per piece lowest.

The question is that how can I do with the material request that the system generated for item A? Just leave it or converting it to purchase order(just save,no submit) what is the different between these 2 methods and what is the best practice?


A minimum stock quantity should be irrespective of anything else, i.e. not depend on a production plan, relationships between other components, or minimum stock quantities of other components. It is a safety check to ensure you always have some quantity of a typically critical part always on hand, e.g. a spare full reel of a hard-to-get component, a spare roll of kapton tape, a spare box of 4-40 screws, etc.

Production planning, or MRP, is an operational system, it takes care of questions like "what do I need to buy in order to build quantity X of assembly Y by date Z. An MRP system takes a bill of materials with supply chain details for purchasing individual parts (with leadtime and quantity price breaks), and desired production quantity and delivery date, and using the component purchasing lead times (and possibly production workstation process times), and tells you when parts should be bought, when, and in what quantities, for you to achieve your production plan.

What is the best practice will depend on what you want to do. Do you want to ensure sure you have some minimal quantity of a critical part always on hand, or do you want to plan the purchasing to build a product based on a sales or production plan?

You can adapt these concepts to your own situation. For example, if you manage minimum stocking quantity of parts but do not use MRP, you could configure appropriate minimum stock quantities that would be sufficient to build some number of finished assemblies.

With relatively small quantities of a relatively small number of BOMs, it might be more convenient and efficient to simply treat each board build as a completely separate production job. Planning will be simpler and you can use simpler tools if you don’t have to take into account whether a part is used on more than one BOM. Separate jobs might even be preferred if the time it takes you to do production planning is greater than the cost savings from buying in greater quantities or issuing fewer purchase orders.

Designers often spend a significant amount of time finding the best part, or the best supplier with the best price, without considering their own time may be the most expensive input to the manufacturing cost - or the opportunity cost of not using that time for something of greater value.

Does that help?


Thank you very much for your reply. I really appreciate with your answer. I know a lot from you!!

I do the trading company so there is no MRP or production.

I just want to know the different between keep the automatic generating material request from system or converting to PO document and just save. Then wait for other items to reach their reordering level.

I can do both option but I am not sure which one that I should do.


Someone familiar with enterprise best practices should comment, but I suspect those people are not users of ERPNext (yet). IMHO it’s the difference between doing the work when a purchasing requirement has been noted (some part is below minimum stocking level) and batching work to do later (saving POs until there is time or justification to process).

IMHO what would be best would depend on your specific situation, such as how many POs you issue a day (or week or month) and for how many different parts, and how critical it is to your business that a PO is issued as soon as you know there is a shortage. It may be there is no “general” best practices (but if there is, I would like to know too).

You may also consider if you want the system to generate POs automatically (and sending without sanity check by a clerk, who doesn’t know if there is a business requirement or not). Software will happily make many many mistakes very very quickly if it is what it has been configured to do.