PM Calendar

What this tool does

CM8-350 takes your recurring maintenance tasks and projects every occurrence forward across a planning horizon, so you can see which weeks are overloaded before they arrive. It totals the hours week by week, draws them against the capacity you actually have, splits the annual load by trade and by criticality, and shows how much room each task has to move.

Everything runs inside this single file — no account, no upload, no network request of any kind.

How this differs from a PM schedule

A maintenance schedule answers "what has to be done to this asset, and how often". This answers a different question: "can we actually do it?"

Most PM schedules are written task by task, each one sensible on its own, and nobody adds them up until the weeks start being missed. The compliance figure then falls and the response is usually to chase people, when the real problem is that the schedule asks for ninety hours in a week that holds forty-two. This tool exists to find that out in advance.

What one row is

One row is one recurring task on one asset — not one occurrence. "Change the filter element every three months" is a single row that generates an occurrence every three months forward across the horizon. If a pump has four different PM tasks at four intervals, that is four rows.

Enter hours as labour hours, not elapsed time. Two fitters for an hour is two hours, because that is what it costs you in capacity. The people field is recorded separately for planning; it does not multiply the hours, so do not double-count.

How occurrences are projected

Everything is projected from the last completion date:

This is a floating schedule: it counts from when the task was last done, not from when it was last due. If a monthly task was done three weeks late, the next one moves three weeks with it. That matches how most maintenance actually works — the point of greasing a bearing every month is that a month has passed since it was greased — but it does mean a schedule can drift permanently later if tasks are habitually done late. The Position column tells you when that is happening.

Why a monthly task drifts

A month here is 30.44 days and a year is 365.25 — the averages. Real calendars do not work that way, so a monthly task lands on the 3rd, then the 2nd, then the 1st across a year, and an annual task can move by a day.

This is deliberate and it is stated on the report. This tool is a workload forecast: it answers how many hours fall in week 14, and a day either side does not change that answer. It is not a diary and should not be used as one. If a task must happen on the first Monday of the month, that belongs in whatever system issues the work.

The weekly load chart

Each bar is the total labour hours of every occurrence falling in that week of the horizon. Bars above the capacity line are drawn in red. Week 1 starts today, not on a calendar boundary, so "W1" means the next seven days.

Overdue work is not carried into week 1. Occurrences before today are stepped past, because a bar containing eight months of arrears tells you nothing about next week's capacity. Arrears are reported separately, in the tiles and the overdue table, where they can be dealt with as their own problem.

Usable capacity, not headline capacity

The capacity line is not your headcount multiplied by 37. It is what is left after breakdowns, projects, meetings, training and everything else that eats a maintenance week. Thirty percent is a common figure in a reasonably controlled plant and forty to fifty is common in one that is not; if you do not know yours, take it from the split between planned and unplanned work orders over the last few months rather than guessing.

Setting this honestly is the whole point. A capacity line drawn at 100% of theoretical hours will show a schedule that fits, and it will still be missed every week.

Tolerance windows

The window is how far a task may move without counting as missed — seven days either side of a monthly task, say. It drives two things: the Position column, which distinguishes "overdue but inside its window" from "missed", and the timeline chart, where the bar is the window and a task with no tolerance is drawn as a diamond.

Statutory work usually has a window of zero: the date is the date, and there is no such thing as nearly compliant. Give routine condition checks a generous one. The tool refuses a window wider than half the interval, because at that point consecutive occurrences overlap and the schedule is fiction.

Levelling the work

When a week is over capacity, there are only four honest moves, and the tool is built to help you judge which:

• Move something. The timeline shows which tasks have room. Move the widest windows first and never move a diamond.
• Change an interval. The annual table shows what each task costs you a year. A weekly check that could be fortnightly halves a line in that table — but only change an interval for a reason you could defend to somebody investigating a failure.
• Reduce the hours. Better kits, better access, a second person to halve the elapsed time on a shutdown task.
• Buy capacity. Contract out the peak. The trade chart tells you what skill to buy, which is usually a more useful answer than "more hours".

What is not an honest move is leaving the schedule as it is and hoping. That is the option this tool makes visibly untenable.

Annual hours

The annual figure is a rate, not a count of what will happen in this calendar year. A task done every four thousand days contributes a fraction of an occurrence a year, which is correct: over a long enough period it costs you that much capacity on average.

What this does not do

• It does not issue, raise or close work orders, and nothing here is a record that a task was done.
• It does not know about shutdowns, holidays or production plans. A week with no production is still a week with 60 hours of capacity as far as this tool is concerned.
• It does not handle condition-based or usage-based triggers. A task due every 500 running hours has to be converted to a time interval at your current duty, and re-checked when duty changes — the sample calendar has one of these in it.
• It does not know your statutory inspection dates. Where a date is set by an inspecting body, it is set by them, and the projection here is only a reminder.
• It does not measure compliance. The target percentage in Settings is recorded for context; proving what was actually done on time needs the completion record, which lives in whatever issues the work.

Printing and sharing

The Report tab prints the tiles, charts and both tables with a title block you fill in. Filter to one trade before printing if you are handing somebody their own load, or to safety-critical work if the audience is a safety committee.

Saving your work

The calendar is held in this browser, on this computer, and stays there between visits. Use the backup button to write a JSON file you control; that file is the only copy that survives clearing browsing data or moving to a new machine. The spreadsheet download gives you the same rows to work with elsewhere.

Accuracy & disclaimer

Every interval, duration and capacity figure here is yours. The tool multiplies and adds them and draws the result; it has no view about whether an interval is safe, whether a task is necessary, or whether the person doing it is competent to. Where the law or an insurer sets an inspection interval, that interval is the one that applies, whatever this calendar shows.