With Dynamics NAV 2013 came the assembly management. It is a great addition to the functionality in Dynamics NAV and gives companies with basic assembly operations a simpler option compared to using the manufacturing functionality in NAV.

The question when implementing Dynamics NAV is then; when do you recommend the assembly functionality instead of the manufacturing functionality and is it wise to use both at the same time?

My approach to manufacturing is always to keep it as simple as possible and to use the functionality that is needed, that adds value and not just because something is available. Most companies want their employees to spend more time producing products and less time interacting with a software (I would the same if it was my company). So, with a simpler way available in Dynamics NAV to convert multiple products into a single product you have to look into if the assembly functionality is more applicable compared to the manufacturing functionality, especially for smaller companies with simpler requirements (the preferred choice is not always obvious).

Here is my check list with questions to ask to determine if manufacturing can be replaced by assembly:

1. Is capacity planning required?

2. Are there long lead times and is WIP required?

3. Do you need phantom BOMs or multi-level production orders?

4. Is there scrap in production that needs to be planned?

5. Will versions of production BOMs and routings be needed?

6. Items going to be sharing BOMs or Routings?

7. Is there any subcontracting involved?

8. Are there processes that has multiple outputs?

If the answer is yes to any of the above questions then the assembly functionality is probably not going to be sufficient. There are probably more things to be added to such a ‘check list’ but the above I think are the main ones.

In addition you always have to consider where the company is going. If it is a start-up that has plans to expand their production then maybe they will outgrow the assembly functionality quickly and because of that using the manufacturing functionality already from start makes more sense.

Then comes the second question; what about using both of them?

Assembly for top level ‘assemble to order’ items and manufacturing for lower level parts that are ‘made to stock’, for example. This is a good question, since the assembly functionality provides some nice interface between the sales orders and assembly orders (availability screen, automatically creation of the assembly orders, calculation of sales price, etc.). This might be a good approach, the biggest downside of this would be that you have two sets of functionality to implement (develop printouts, migrate data, train users, do work instructions for, etc..). I think if it is need to use the manufacturing functionality then you might as well run everything through manufacturing, you can simplify the manufacturing functionality a lot (using flushing etc..) and only have to maintain one set if BOMs will be less confusing for the users as well I think.

In the end it is always what the best is for the customer that should be implemented.