ERP OperationsFree worksheetPDF, Excel, Word exportDiscrete Manufacturing

Plant IT and OT Asset Inventory Worksheet

You cannot patch, segment, insure or replace what you do not know you have. This worksheet is a practical asset register for a manufacturing plant that covers both IT (servers, workstations) and OT (PLCs, HMIs, industrial switches), tagged with Purdue zone and support dates, and exports to Excel.

Download:

Asset ID	Description	Type	Purdue zone	Owner	OS or firmware	Vendor support ends	Age (years)	Planned life (years)	Life remaining (years)	Qty	Replacement cost each	Replacement budget
									1			$18,000
									-1			$12,000
									2			$4,400
									4			$19,000
									6			$7,500
									2			$9,600

Total units

Total replacement budget

$70,500

Lowest life remaining

-1

Average budget per asset line

$11,750

Asset lines

Add one row per asset or per identical group. Sort by vendor support end date to find end-of-life items, and by zone to see which Purdue levels hold the oldest equipment. Negative life remaining means the asset is past its planned life.

Optional help loading assets into your ERP

Tell us your ERP and we will outline how to map this register to its asset or equipment records.

Optional. The tool and every export work without this. No spam.

How to use the worksheet

Replace the sample rows with your own. Walk the server room, control cabinets and production cells, and record each asset once with a stable ID. Fill in zone, owner, software or firmware version and the vendor support end date from the vendor's lifecycle page. Planned life and age give a remaining-life figure per row, and quantity times replacement cost gives a budget. Export to Excel and sort or filter by the columns that matter to you.

Start with the most critical lines, then expand
Use the asset tag on the device as the ID
Record firmware versions, not just model names

What to record and why

The minimum useful set is identity, location or zone, owner, software version, support end and cost. Zone shows whether a device sits in the plant or the enterprise network, which feeds segmentation work. Owner makes sure someone answers for patching. Support end dates reveal operating systems that will soon lose security updates, which is a recurring issue with HMIs on old Windows versions. The replacement cost line helps turn a technical problem into a budget request.

Reading the results

Sort by life remaining to see what needs budget in the next one to three years. Sort by support end to see what will stop receiving vendor fixes. Group by zone to find old equipment in sensitive layers, for example an unsupported HMI at Level 2. The total replacement budget is a rough planning figure, not a quote. Treat a PLC at ten years old differently from a laptop at ten years old, because the replacement effort and risk differ by far more than the price.

Common mistakes

A one-off spreadsheet that nobody updates is the main failure, so name an owner and a review date, ideally tied to change management. Another is inventorying only IT devices and leaving out OT assets that vendors maintain. Teams also forget virtual machines and cloud services, which belong in a separate sheet or additional rows. If you can, compare the register against a network scan or switch MAC tables to find devices nobody listed.

Frequently Asked Questions

How is an OT asset inventory different from an IT one?

OT assets such as PLCs and HMIs often lack agents, scan poorly and are maintained by vendors or controls engineers, so inventory needs walkdowns and passive discovery. They also have longer lifecycles and firmware rather than regular patches.

How often should the inventory be updated?

Review at least yearly, and update whenever equipment is installed, moved or retired. Linking it to change management is the most reliable way to keep it current.

Should software licenses be included?

Track them in a separate sheet or add columns if you prefer one register. The key link is software or firmware version per device, since that decides patching and support status.

Can this replace a CMDB or asset management tool?

For a single plant or a start, yes. Larger companies with many sites outgrow a spreadsheet and need a CMDB or OT asset discovery tool. The worksheet is also a good requirements list when evaluating those tools.

If you want your asset register to feed ERP maintenance and spares planning, Netray can help connect it to your ERP asset module. Ask for a short scoping call.

Talk to an Expert Explore More Free Tools

Related Tools

Industry Templates

More ERP Operations tools

See all

Back to All Tools