The two fundamental modules (if you call them) in Dynamics 365 Field Service are Inventory and Work Management. How does Product Inventory works with Work Orders and products consumed in the field, what triggers the change in inventory number, and how does this relate to status of the products – is the topic of this article. So the agenda is to have a look at how products are added, estimated and consumed in the Work Order and how the impact mirros in Product Inventory.
Before jumping on to the system, let’s spend a few minutes on how product inventories are maintained in different businesses from the field service perspective:
- You run a business to install network devices, your field technicians carry network devices in vans and once they install at client premises, then inventory numbers are updated
- You run a maintenance business and your field technicians are sent out on support tickets to visit client premises and fix installed equipment. At the time of departure from head office/depot, field technicians don’t always know what needs to be carried in the van to fix the equipment so they always carry necessary tools and place extra consumables/materials in the van. In this case, as soon as field technician estimate products to be picked up from the store, inventory numbers are updated to reflect that products are earmarked for the specific support ticket
The difference in these two field service businesses is in the timing of the inventory updates:
- In the first one, inventory is updated only when products are ‘used’
- In the second scenario, inventory is updated as soon as it is estimated
Dynamics 365 Field Service supports these both scenarios. The behaviour of the product could be set from the settings. Go to Field Service Settings, click on Other and set ‘Auto Allocate Estimate Products’ to No for the first scenario and Yes for the second scenario

1. Inventory update when products are consumed
Go to Inventory under Field Service app and click on Product Inventory.

Note we have 25 Universal Network Cards available. Let’s create a Work Order Product estimate ‘3’ to be used.

Go back to inventory and you’ll see no impact of this on the inventory numbers.
Open the Work Order Product record again and this time add ‘2’ as the actual quantity and change the status of record as ‘used’.

Go back to inventory to see if inventory numbers are now updated:

They surely did – please note inventory is now updated as 23, thus system deducted the used quantity (2), not the estimated quantity (3).
2. Inventory updates when products are estimated
Go to Inventory under Field Service app and click on Product Inventory.

Note we have 23 Universal Network Cards available.
Next, create a Work Order Product against a work order and let’s estimate ‘5’ to be used

As soon as you save the record, go back to inventory to see the difference:

Inventory numbers are updated to record now only 18 are available while rest of 5 are allocated.
Hope you find this useful, if you have any questions feel free to reach out. I also found product documentation as a good reference for this functionality area.