During procurement, have Finance and/or Internal Audit create and maintain a formal asset-registration process. All people managers must receive all procured devices/software and each approved vendor must provide a list of inventory services. Gaps in the inventory services automatically provided from the VARs must be filled in by the people managers using a checklist.
Business Process Example
People manager decides to procure an iPhone and an Android-powered thermostat for a remote worker who is a thermostat tester. The VAR who works with Apple provides the serial numbers, SIM card identifiers, telecommunication-provider IMEI, and MAC address for the WiFi component of the iPhone. The people manager turns on the iPhone to collect the Bluetooth BDADDR and submits it to the internal procurement asset-registration portal using a Standard-Operating Procedure (SOP) document. The manager then opens the box containing the thermostat, turns it on, and collects its WiFi and Bluetooth MACs using a separate SOP document in order to submit these to the procurement asset-registration portal.
At this time, I do recommend tracking at least SIM serial, IMEI/MEID, as well as Ethernet and Bluetooth MAC addresses. You may also want to track ZigBee, Z-Wave, RFID, and NFC identifiers.
Technology Platform Examples
SAP or Oracle Hyperion typically have ways of documenting procurements to asset codes to plant codes. For example, you can have SAP ECC document what was purchased when and where it went, perhaps down to the PDU level, e.g., a cage in a data center or a cube on a floor of a particular building.
Then the procurement system can have hooks to the IT/Ops CMDB or configuration-management database. Some of these include: Axios Assyst, BMC Atrium, CA Service Desk Manager, Cherwell Software, Freshservice, FrontRange, Hornbill, HP Universal UCMDB, IBM SmartCloud Control Desk (SCCD), iET Solutions, InvGate Assets, LANDESK Service Desk Suite, ManageEngine IT360 / ManageEngine AssetExplorer, Scalable Software, ServiceNow, SolarWinds Web Help Desk, and SysAid. If you want free, open-source projects to track inventory and configuration management, check out clusto.org, https://github.com/mozilla/inventory , or http://fusioninventory.org/overview/ -- (with -- https://www.fusiondirectory.org -- and perhaps -
Additionally, you can even link applications to an app inventory (or app portfolio, part of Enterprise Architecture Management aka EAM) with device inventory. Microsoft SCCM can do this with software tagging (either ISO/IEC 19770-2 and/or SWID tagging), but there are other solutions that do full EAM such as Software AG Alfabet.
IoT devices, in particular, leverage either on-device REST APIs or reach out to cloud-based REST APIs. These can be discovered, tracked, and managed using Application Discovery and Dependency Mapping (ADDM) solutions such as AccelOps, Cisco AppDynamics, AppEnsure, VNT IllumIT, and -- my favorite for its ability to integrate back to the CMDB -- ServiceNow ServiceWatch.