Microsoft's lifecycle page for Dynamics NAV 2018 gives two dates. Mainstream support ended on 11 January 2023. Extended support ends on 12 January 2028. NAV 2018 was the last version of NAV, and Business Central replaced it in 2018, so every NAV estate still running in September 2026 is on a product with sixteen months of security patches left and nothing after that.
That's the deadline. It isn't the reason most of these projects are hard.
The customisation is the project
A NAV system that has been in a warehouse for ten years has a warehouse module that no longer resembles the one Microsoft shipped. Somebody added handheld scanning. Somebody made a pallet of mixed items scannable as one thing. Somebody wired the shipping label to the sales order. Each of those was written in C/AL, directly into the base objects, and each upgrade since has meant paying a partner to carry them forward.
Business Central doesn't allow that. Customisations are AL extensions that sit beside the base application, which is what lets Microsoft update it monthly without breaking your floor. The upgrade is not the migration of data. It's the decision, object by object, of what happens to the code.
There are three answers for each one. An app replaces it. An extension rewrites it. Or nobody uses it any more and it can go. The proportion between those three is what decides whether the project is four months or fourteen, and it can't be estimated from a demo. It has to be inventoried.
Where Insight Works changes the arithmetic
The warehouse customisations are the expensive ones, and they're also the ones that have become products. Insight Works sells Business Central apps for the four things every warehouse asks for. Warehouse Insight puts picking, put-away, movements and counts on a handheld. License Plating makes a mixed pallet one identifier and one scan. Shop Floor Insight captures production time and quantities by barcode at the work centre. Dynamic Ship pulls carrier rates and prints labels from inside the order.
We know what those customisations cost to build because we built one. Funko's warehouse system, on this site at /case-studies/funko, needed license plating and the ERP didn't have it, so we wrote it. It doubled throughput efficiency and it was the right call in the year it was made. Today we'd configure the app, because an app survives the monthly update and code written into base objects doesn't.
So the inventory of customised objects usually comes back with the warehouse column mostly reading "app replaces it", and the finance column mostly reading "extension rewrites it" or "not needed". That's the shape that makes a NAV move affordable, and it's the reason we became an Insight Works partner alongside the Microsoft designations we already hold.
The part after go-live
A cutover weekend is a milestone. Production starting is the test.
Cyclic Materials, which recovers rare earths from end-of-life products, runs Business Central with Insight Works at its facility in Mesa, Arizona. In August 2026 they found this site looking for on-site help with warehousing and production transactions as production ramped, and engaged us to provide it. What they needed wasn't another implementation. They needed an engineer on the floor when a pick posted wrong, from an office in Gilbert that borders Mesa, rather than a support ticket answered the next morning from another time zone.
That's worth planning for from the start. A NAV to Business Central project that ends at go-live leaves the floor holding a new system and a new set of handhelds on the day the volume arrives. Hypercare staffed by the people who built the configuration, for as long as the first close and the first full week of production take, is the difference between a system people trust and one they route around.
What the move actually contains
In the order it happens.
- An inventory of every customised object, with the verdict written beside each one. This is two to three weeks and it produces the estimate.
- Business Central set up properly underneath. Locations, bins, zones and put-away rules designed against the physical floor, because an app inherits a location structure and cannot repair one.
- The Insight Works apps installed and configured against that structure, and the handheld paths tested by the people who will use them.
- Data migrated and reconciled in rehearsals. Opening balances, open orders, item history and inventory by bin, agreed with finance and operations before the freeze.
- A dated cutover with a rollback somebody has read.
- Hypercare, on site where the site is in reach.
If you're on NAV and the date has started to matter, the inventory is where to start, and it's a complete piece of work on its own. Talk to an engineer or read what the Dynamics 365 practice covers first.