thats how it works for me, ok I'm not sure then

If the Manufacturing Work In Process (WIP) feature has been enabled, you can use SOAP web services to interact with work order close records. You can check to see if WIP is enabled by going to Setup > Company > Enable Features, and reviewing the Items & Inventory tab. With WIP, instead of creating a single assembly build record to denote that a work order has been addressed, you track progress of the work using three records: work order issue, work order completion, and work order close. This approach lets you manage the assembly process in a more granular way, and to keep the General Ledger up to date as materials move through the different phases of assembly.

sounds like it's this WIP feature

your saved search pulls assembly builds instead of work orders, then you have access to the date you built them, which translates to completion date

in that search you can have a result column with a created from work order name field, so it looks like a WO search

Thanks

I see no built in completion date field on a WO.

completion date may be different from the date the work order was fully built. if so those methods wont work. https://netsuite.custhelp.com/app/answers/detail/a_id/27934