A device costs money three times: when it is bought, every month it is managed, and on the day it leaves. Lifecycle management is the attempt to hold all three in one record, and the reason it is hard is that only the middle stretch has an agent reporting on it. Purchase, warranty and disposal are paperwork, and paperwork is where an asset register stops matching the fleet. NIST's IT asset management guidance makes the same point from the security side: a physical asset system can tell you where a computer is and not what it is running.
Ask vendors to quote against your actual endpoint count
ITAM asset management is the register, and the agent is only half of it
What the agent gives you is authoritative and narrow: the machines that are switched on and reporting, with their hardware, software and patch state. What it cannot give you is the machine in a drawer, the one on order, the one a leaver took home, or the warranty that expires in March. Those come from purchasing and from a process, and the register is only as good as the weakest of the two. The practical test of any ITAM claim is whether it can show you the difference between the two lists, because that difference is the whole of the risk.
Device inventory: what an agent can prove and what it can only suggest
A device inventory built from an agent is a strong claim about what it can see and silent about everything else. It proves this machine exists, is running this build and has this software on it. It suggests, at best, that a machine which stopped reporting three weeks ago is gone rather than switched off. Treat a machine that has not checked in for a stated period as an exception to be closed by a person rather than a row to be deleted, and write the period down, because a register that quietly forgets machines is worse than one that is obviously incomplete.
IT lifecycle management software, and the part that happens after the agent stops reporting
Disposal is the stretch nobody demonstrates. A device leaving the fleet needs its data made irrecoverable and the fact recorded, and NIST SP 800-88 Rev. 1 sets out the categories of sanitisation and includes a certificate template for exactly that record. Whatever tool holds the register, the questions are the same: who wipes it, what evidence is kept, and does the register show the machine as disposed rather than merely absent. An MSP that can answer those three in front of a client's auditor is selling something the client cannot easily replace.
Questions people ask about it lifecycle management
What does IT lifecycle management actually cover?
Procurement, deployment, the managed life of the device, and retirement. The middle part is what an RMM evidences; the two ends are purchasing records and a disposal process, and they are where registers drift out of date.
Can an RMM be my asset register?
For what is switched on and reporting, yes, and it is the best source you have for that. For what was bought, what is in storage and what has been disposed of, no, because nothing is running to tell it.
Does a discovery sweep cost more?
It can. Where a vendor counts endpoints, anything the sweep finds and agents can be a billable device. Ask what counts as an endpoint before you widen the net across a client's network.
What evidence should a disposal leave?
A record naming the device, the method used and who performed it. NIST SP 800-88 Rev. 1 carries a sample certificate of sanitisation for the purpose, and a client's auditor will ask for something of that shape.