If you need GPS to locate the techs, you need to check the management. Techs who don't answer phone or radio should be brought in for conference and told how it will work. We had that issue at another place I was employed and I told my boss the same thing. It's a management issue. Disciplinary action will make one answer their phone. And before anyone jumps, yes, I am a tech, and have been sent many miles out of the way because someone wouldn't answer their phone( during business hours) causing customer to pay extremely large travel times. Finally convinced the bosses that each tech should be responsible for a specific area and learn the lifts in their area. There are exceptions but they are few.

I`m very surprised to hear that some dispatchers cannot locate their techs. I thought GPS`s were an industry standard. We have had them for 6 years, and most other dealerships have them too or are planning on getting all trucks fitted with them. If your company cant afford a GPS system, The iphone has a free GPS APP that works quite well. Your fellow techs can even see you, and you see them. Works out great when parts guy says ``John has that part you`re looking for in his van`` You check your phone and John is 2 blocks away. Any company needs cell phones so if you dont have a GPS service in your trucks, switch to iphones.
The `Find my friend``is the only useful thing about an iphone which is not friendly to the fingers of middle aged techs!

It certainly makes it easy for the dealer to pass the buck- when you're having an issue with a particular unit, their "guy" for that brand is from another dealer, so now 1)- you can approve that another tech who's not as saavy try to fix a problem ( & pay for elongated time 'cause he's spinning his wheels or 2) wait for their "guy" & pay for elongated travel time & hope he doesn't need parts ( he can't go to the local dealer for parts- he has to go to his home dealership). Either way it's a lose- lose situation for the customer.

When the salesman knocks on the door- he sells the multiple brand/multiple dealership as a plus- it all goes downhill once you actually use their services

agreed,it's not the problem of multinranding and multiple locations,but the service and technology something...

I think, that multibranding and multiple locations are different issues.
The case you describe shows rather non-professionalism/greed from the service company.
I don't believe in that "dispatching softwares" which automatically decides who goes where. This is a quality flop.
There's always a human dispatcher/coordinator who knows (or should know) how to optimize the operation. Not forgetting some simple marketing issues like "one face to the customer", or technical (I know this machine for years).