Failed: Device assigned on Apple Business Manager.

Is the device assigned to your MDM? If so, you can assign it and reassign it to as many MDMs as you want as often as you want. The only action that is a one time action is releasing a device from ABM. Disassociation occurs when your legal business entity is transferring, selling, or disposing of hardware and it will no longer be used by you business. That is the only time you should release a device from ABM. Once removed, you can not add a Mac back.

If it is still listed in ABM but unassigned to an MDM, simply assign it back to your desired MDM. Keep in mind, if the unit is already set up and running, this assignment will have no impact to the device in production. If the device is idle, you should erase and reinstall the device after reassigning to your MDM. By doing so, you will then be able to complete an automated enrollment process. Assignment to an MDM can take 5 minutes to a day to be reflected in your MDM depending on which one you use. For MDMs that have longer poll times there is often a force sync option.

In ABM you have three actions. Assign to Server, Unassign Devices, and Release Devices. As mentioned, Release Devices should ONLY be used when you are disposing of hardware and want to disassociate the asset from your legal entity. This is the only one time, non-reversible action when talking about Mac devices.

Reid

You start with enrolling in Apple Business. https://business.apple.com

For this you need a DUNS number and the address on the DUNS record must match you current business address. Current your DUNS record before attempting to limit delay and repeating the process. It usually takes about 3 to 4 days to complete Apple Business Manager enrollment and will require a phone call with Apple. You can do this yourself from the link above. Or work with your Apple Store Business Team or Reseller/Integrator if help is needed.

Once you have Apple Business setup, then you need to integrate into your MDM. Tokens will be available to link to Apple's deploy program and App Store volume purchasing program. These will need to be installed into your MDM. From there, you set up a pre-stage enrollment policy or a provisioning profile (each MDM calls it something slightly different).

Also, please be aware that only devices purchased by your legal business entity are eligible for automated enrollment. You can not just walk in and buy from retail or with a personal credit card. Work with your Apple Store Business Team or DEP authorized reseller to ensure that purchases are linked to your Apple Business Account. While you can side load iOS devices using Apple Configurator, you can not side load Mac devices (side loading of iOS devices have a 30 day opt out period). If you want automated enrollment, make sure you purchase the products properly. Apple Business is about proving chain of ownership as much as it is about setting the foundation for simplified deployments.

If you have a relationship with a good reseller or have always been buying from Apple Business, you should be able to get all prior purchased made by your legal business entity linked to your Apple Business account. However, this will not alter the current deployment of the devices. Enrollment automation occurs at system setup. So existing devices can be manually enrolled into your MDM (and user approve MDM enrollment on 10.13.2 or higher) or you will need to wipe them to experience Setup Assistant. In most cases, the logical workflow is to back load all prior purchases and then through natural attrition, nuke and pave the devices to get them enrolled through automated enrollment (basically, when staff turns over, reset the machine).

This is very powerful technology and generally easy to setup (this is Apple technology after all). Do your research on the various MDMs to make sure you are selecting one that fits your needs. Test, test, and test some more with demo gear. Getting automated enrollment setup has limited settings but the setting and software delivery beyond that can get complicated.

Again, the basics are:

Start by enrolling in Apple Business

Link Apple Business to your reseller or Apple Store Business Team

Select an MDM and integrate it with ABM

Consider back loading previous business purchases

Understand that existing, in production systems will not be impacted by back loading

Enjoy the journey. Great thing to do. Significantly reduces IT overhead. We drop ship systems all over the country and end users set them up. Easy.

Reid Bundonis

Apple Consultants Network

Hello budiss-grc,

​Thank you for using the Apple Support Communities. I see you have a question about Mobile Device Management.

If you're a system administrator, these resources may help you:

Apple Business Manager User Guide

Get started using Apple Business Manager or Apple School Manager with Mobile Device Management

You might find additional resources and guidance here as well: Business Support

I hope this helps get you started! Best wishes.