Every chief engineer who's ever managed a superyacht's maintenance has, at some point, opened Excel.
It makes sense. The boat needs a system. The previous chief had a spreadsheet. The budget for software hasn't been approved. Excel is free, it's already installed, and it can do anything if you set it up right. So the spreadsheet gets built — equipment list on one tab, maintenance schedule on another, spares inventory on a third — and for a while, it works.
Then the boat goes through a busy charter season. Or the chief leaves. Or someone copies the file to OneDrive and breaks the formulas. Or the management company asks for a maintenance report and it takes two days to produce.
This article is about what actually happens when spreadsheets are doing the job of a purpose-built planned maintenance system — and what changes when crews finally make the switch.
The honeymoon period
Spreadsheets are seductive. The first version takes a weekend to build, costs nothing, and feels in control. You can see everything on one screen. You can sort, filter, color-code. The chief who built it understands every formula. The captain trusts it because they helped design it.
For the first six months, it might genuinely be the best system the boat has ever had — especially compared to whatever was inherited from the previous chief, which was probably worse.
The problems start later. They start small, then compound.
Where it starts to break
Version control becomes a nightmare
The first crack is usually around file management. The chief has the master file on their laptop. They share it with the captain, who saves a copy to make notes. The second engineer has a version from three weeks ago. Someone emails the spreadsheet to a contractor for a quote, and the contractor sends back a "marked-up" version with helpful suggestions.
Within a few months, there are five files named some variant of Maintenance_Schedule_v3_FINAL_actually_final.xlsx, and nobody is entirely sure which one is current.
This isn't a hypothetical. It's the first thing that breaks on every spreadsheet-managed yacht, and it breaks the same way every time.
The chief leaves and takes the system with them
Spreadsheets carry their author's mental model. The naming conventions, the formula choices, the color-coding scheme, the rules about which tab gets updated first — all of it is in the head of whoever built it.
When that person leaves the boat, the next chief inherits a file they didn't build, full of formulas they didn't write, structured according to logic they have to reverse-engineer. Most of them don't bother. They start over. The maintenance history of the previous two years gets archived to a folder nobody opens, and the new chief begins building their own spreadsheet from scratch.
Multiply that across a yacht's lifetime, and you end up with operational continuity that resets every few years.
Formulas break in ways nobody notices
Spreadsheets are fragile. A misclick in the wrong cell, an autocomplete that overwrites a formula, a row insertion that breaks a reference, a copy-paste that corrupts a date format — any of these can silently break the system without anyone realizing it for weeks.
The 250-hour service that should have generated a reminder doesn't. The certificate expiry that should have flagged red shows green. The inventory count that should have triggered a reorder shows stock that doesn't exist.
You discover the broken formula when something fails. By then, you've already missed the maintenance, or run out of the spare, or shown up to an audit with a certificate that expired three weeks ago.
Multiple people can't actually work on it at once
Cloud-based spreadsheets (Google Sheets, Excel Online) help with this somewhat, but only somewhat. Real-time collaboration in a complex spreadsheet is a recipe for accidents — people typing over each other, formulas getting overwritten, filters getting changed mid-edit.
In practice, most spreadsheet-managed yachts revert to a "one person owns it" model. The chief updates the spreadsheet. Everyone else looks at it. When the chief is on leave, the system pauses.
That's not a maintenance system. That's a single point of failure with cells.
Reports take days to produce
When the management company emails on Tuesday afternoon asking for a list of all maintenance overdue across the fleet, the chief on a spreadsheet-managed boat is looking at half a day of pivot tables, filtering, and manual cross-referencing. Sometimes more.
The data is technically there. Extracting it in a usable format is the problem.
The same is true for ISM audits. The auditor wants to see maintenance history for specific equipment over the last 12 months. The spreadsheet has the data, somewhere, in a format nobody designed for that question. The chief spends three days preparing for the audit instead of doing actual work.
There's no audit trail
Who marked that task complete? When? What did they actually do?
In a spreadsheet, the answer is "we don't know." The cell got changed at some point. There's no log, no timestamp, no signature, no record of who touched what. The previous value is gone the moment someone overtypes it.
For ISM-coded vessels, this is more than an inconvenience. The Code requires evidence of maintenance activities and the people who performed them. Spreadsheets can't produce that evidence in any rigorous form.
Spares and equipment are managed separately
A spreadsheet might track spares on one tab and equipment on another. They don't actually talk to each other. When you complete a maintenance task that uses two oil filters, the inventory tab doesn't update automatically. Someone has to remember to deduct them. Most of the time, nobody does.
The result is a spares inventory that diverges from reality over time. By the time you discover the gap — usually because you reach for a part that should be there and isn't — the trust in the inventory system is gone.
Mobile and offline use is awful
Engineers do their work in engine rooms, not at desks. Logging completed tasks onto a spreadsheet from a phone, in poor lighting, on a swaying boat, is miserable. Most crews don't bother. They either remember to log everything later (and forget half of it) or maintain a paper notebook in parallel that gets transcribed weekly (or doesn't).
Either way, the spreadsheet is no longer a real-time system. It's a record of what someone remembered to write down at the end of the week.
What changes with purpose-built software
The shift from spreadsheets to a proper planned maintenance system isn't about features. It's about all of the above problems going away at once.
Version control disappears because there's only one system, accessed by everyone, always current.
The chief leaving stops being a crisis because the system isn't in their head — it's in a database, structured the same way for everyone, with a maintenance history that survives crew changes.
Tasks generate themselves on scheduled intervals. Nothing relies on someone remembering. Reminders fire automatically as deadlines approach.
Reports are runnable on demand. The management company asks for an overdue maintenance list, you click a button, you send it back ten minutes later.
Audit trails are built in. Every action is logged, timestamped, and attributable. ISM audits become routine instead of project-managed.
Inventory is linked to equipment. Completing a task that uses spares automatically deducts them. Stock levels are real-time. Reorder thresholds trigger automatically.
Mobile use is designed-for, not retrofitted. Crews can log completed work from a phone in the engine room without fighting with frozen Excel cells.
This isn't a sales pitch. This is the difference between a system designed to do this job and a tool you've forced into doing it.
When does the switch actually make sense?
Honestly: when the spreadsheet starts costing more time than it saves.
For a small yacht with simple equipment and a stable crew, a well-built spreadsheet might be fine for years. The economics of switching to dedicated software don't always justify the change.
For a charter-coded yacht above 30 meters, or any vessel where the chief has changed in the last two years, or any boat where audit prep has ever felt like a fire drill — the math has usually flipped. The hours lost to spreadsheet maintenance, version reconciliation, audit preparation, and missed-reminder consequences add up faster than the cost of proper software.
Most crews who finally make the switch tell us the same thing afterward: they wish they'd done it two years earlier.
What to look for if you're considering switching
A few questions to ask of any platform you evaluate:
- Was it built for superyachts specifically, or is it a generic CMMS? Generic systems handle 80% of the use case. The remaining 20% — the parts that are unique to yacht operations — is where they fall short.
- Does it work offline? Yachts spend time at sea or in remote anchorages. A platform that requires constant connectivity is going to fail when you need it most.
- Can the crew actually use it from a phone? If logging a completed task takes more than 30 seconds in the engine room, adoption will be a problem.
- What does data import look like? Migrating two years of spreadsheet history into a new system is the activation barrier. The vendor should make this painless.
- Who built it, and how long have they been supporting yachts? This is software that has to work at 0300 mid-Atlantic. The team behind it matters.
YMS360 was built around exactly these requirements — purpose-built for superyachts, supported by a team that's been in the industry since 1999, with 12 modules covering the full operational lifecycle. If you've been wrestling with a spreadsheet that's outgrown its useful life, we'd be glad to show you what the alternative looks like.