A van that is always loaded sits differently from one that is not
Alignment is measured with the vehicle at a particular ride height, and the specification assumes something about how the vehicle is normally laden.
A delivery van that carries several hundred pounds of stock every working day spends its life sitting lower at the back than an empty one of the same model. The suspension is compressed, and compressing a suspension changes the angles the wheels sit at.
Which raises a reasonable question when such a vehicle goes on a rack: measured empty, is it being set up for a condition it is almost never in?
That is a conversation worth having rather than assuming either way. Tell the store the vehicle runs loaded, roughly how much, and whether the load is permanent or varies. What the manufacturer specifies, and what is sensible for your vehicle, is a question somebody looking at it can answer properly.
The point is that it is a question at all. Most vans are measured without anybody mentioning it.
Why it shows up on tires
A vehicle habitually running at a different ride height than its alignment assumed wears its tires accordingly: usually an edge rather than the center, and usually consistently across the fleet because all the vans are loaded the same way.
Fleet-wide uneven wear with no obvious cause is worth examining in that light before anybody blames the tires.
When to book it
The national alignment page covers the occasions. An alignment that will not hold is suspension, handled at this store, with the alignment afterwards.
About this store
The Springdale store runs eighteen services, carries all nine Purcell tire categories, and is managed by Jackie McAfee. It also aligns heavy trucks and trailers.
See the national car and light truck alignment page for all 40 locations.