Maintenance schedule in Excel: the columns, the formula and a template to copy

What is a maintenance schedule in Excel?

A maintenance schedule in Excel is a single table with one line per installation you maintain. The fixed columns are the customer, the site, the installation, the type, the last visit, the frequency, the next visit, the technician and the status. Excel calculates the next visit itself, and a colour shows what is overdue or due soon.

What happens at each type of maintenance, and how often, is the maintenance plan itself: see preventive maintenance. How you record the arrangements with the customer is covered in tracking maintenance contracts. This article is about the list that brings it all together.

Where the data sits today

In most service companies, the information for a maintenance schedule is scattered:

• in the calendar of whoever once sold the maintenance;
• in a list per technician, on paper or on their mobile phone;
• in last year’s invoices: who paid for maintenance then?
• in contracts in a folder, with the frequency somewhere in the text.

Each source knows part of it. The first step is to bring them together in one table, with one line per unit. So a customer with three units gets three lines.

Making a maintenance schedule in Excel: the columns

Three conventions keep the list usable:

• Dates as real dates. Excel cannot add to or compare a date that was typed in as text.
• Type and status from a drop-down list. With Data Validation (Data tab), everyone chooses from the same words. Otherwise “boiler”, “CH” and “gas boiler” get mixed up and no filter works.
• Access and contact person in a Notes column. Key with the caretaker, gate code.

Calculating the next maintenance date

The formula for the next visit, in words:

A few practical points:

• Give the Next visit column a date format. Otherwise, Excel shows a number.
• In Excel with Belgian regional settings, you usually separate the arguments of a function with a semicolon.
• If you work with an interval in days, simply add the number of days to the date of the last visit.
• Decide what you count from. If you count from the last visit carried out, a late visit pushes the next date back as well. If a boiler must be serviced every year before the winter, count from the planned date, so that the visit stays in its season.

Colours for overdue and due soon

With Conditional Formatting (Home tab), Excel colours a line according to a condition. Choose a rule that uses a formula and apply it to the whole table, so that the entire line changes colour. Three colours are enough:

• Red: the next visit is before today and the status is Open. That visit is overdue and not yet scheduled.
• Orange: the next visit falls within 30 days and the status is Open.
• Grey: the status is Paused, for example because the customer has had their unit replaced.

Put the red rule at the top of the list of rules, so that it takes precedence. Also put a filter on the header row, so that one click shows only the red or the orange lines.

Maintenance schedule in Excel: a template to copy

An example with fictitious data, viewed on 31 October 2026. Copy the columns and replace the lines with your own installations.

On that day, the first line turns red, because the visit is overdue and not yet scheduled. The second is also past its date, but the visit is already in the calendar: no colour. The third turns orange. The fourth stays white.

How to use the list every week

1. Choose a fixed moment, for example Monday morning, and one person who keeps the list.
2. Filter on red. Call those customers this week. If that does not work out, note why in the notes.
3. Filter on orange. Schedule the visits for the coming weeks, grouped by area, and set the status to Scheduled.
4. Update the list after every visit. Enter the date under Last visit and set the status back to Open. The next visit adjusts itself.
5. Add new installations straight away, with the installation date as the starting point.

How you then fit those visits into your technicians’ week is covered in a technician schedule in Excel.

Where a spreadsheet stops

As long as one person keeps the list, a spreadsheet works. It pinches in four places:

• Several people work in it. The planner and the owner each have a copy, or someone sorts a single column and the lines get mixed up. Which version is right?
• No link with the technician’s app. The list only knows that a visit has taken place when someone types in the date. On site, the technician cannot see what happened last time.
• No history per installation. A line only keeps the last visit. What was measured, replaced or found is in other files. Why that matters is explained in the service history per installation.
• Invoicing. The list does not know what is included in the contract, what was extra and what has already been invoiced.

An example: a heating company sets up its list

A heating company with three technicians builds a single list over the summer from the calendar, the invoices of the past two years and the technicians’ own lists. Each unit gets a line, a type from the drop-down list and a frequency. At the first Monday check, a series of lines turns red: boilers that were serviced last year and had not been scheduled again anywhere. The planner calls those customers first and groups the visits by municipality.

After one heating season, the owner sees where it chafes. The technicians report their visits on paper work orders, and there are sometimes days between the visit and the new date in the list. The owner decides to move the list to software, without typing everything in again.

How it works in Digitalnatie Service Suite

In Service Suite, your Excel list becomes a series of maintenance contracts.

• From Excel to Service Suite: in the data import screen, you import the customers, the sites, the installations and the maintenance contracts, in that order. For each type, you download an Excel or CSV template with the list of required columns. The check writes nothing yet and shows which lines are correct; only lines without errors are imported.
• One contract per line: in the maintenance contracts screen, you create a contract for one installation or for a whole site, with a frequency (monthly, quarterly, half-yearly, yearly or a custom number of days), an optional technician and the date of the next visit. The form shows the next six dates.
• The visits: once a day, for each active contract whose next visit has been reached, Service Suite creates a preventive maintenance intervention, with the contract’s technician if there is one. The next visit then moves on by one period, and you schedule the visit like any other intervention.
• Your colours: the screen has tabs for overdue visits and for visits within the next 30 days, with a key figure for each, and a tab for the contracts that end within 60 days.
• An extra visit: you schedule it from the contract.

Good to know:

• Without a site, Service Suite does not create any visits.
• The automatic visits are created once a day, and you cannot start this manually. Missed visits are not created afterwards.
• A contract has no price of its own: the annual price is the same for all active contracts. Per contract, however, you choose whether the visit, the hours above the minimum and the parts are billable or included.
• An import cannot be undone with one click, and a file is at most 10 MB. Start with a small file.

More about maintenance contracts in Service Suite. How to prepare your data is explained in importing customer data.

Frequently asked questions

How do I make a maintenance schedule in Excel?

Make one table with one line per installation and the columns customer, site, installation, type, last visit, frequency, next visit, technician and status. Let Excel calculate the next visit and use conditional formatting to colour what is overdue or falls within 30 days. Check the list every week at a fixed moment.

How do I calculate the next maintenance date in Excel?

Add the frequency in months to the date of the last visit, with the EDATE function (ZELFDE.DAG in Dutch-language Excel). If you work with an interval in days, simply add the number of days to the date. Give the column a date format, otherwise Excel shows a number.

Is there a free template for a maintenance schedule in Excel?

You can copy the example in this article for free: copy the columns into a blank spreadsheet and replace the example lines with your installations. Then add the calculation of the next visit and the colours as described above.

How do I colour overdue maintenance in Excel?

Use conditional formatting with a rule based on a formula, applied to the whole table. Red if the next visit is before today and not yet scheduled, orange if it falls within 30 days. Put the red rule at the top, so that it takes precedence.

Can I import my maintenance schedule from Excel into Service Suite?

Yes. In the data import screen, you import customers, sites, installations and maintenance contracts with Service Suite’s Excel or CSV templates. The check beforehand writes nothing, and only the lines without errors are imported.