BIZOMAT Tools · Manufacturing
Downtime Cost
What does downtime really cost?
Estimates the cost of a downtime event from lost contribution, idle labour and restart cost.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Downtime | hr | Duration of the stoppage |
| Lost contribution / operating hour | $/hr | Contribution lost per operating hour (sales value minus variable cost) |
| People affected | people | People unable to work productively |
| Loaded labour rate | $/hr | Loaded labour rate |
| Restart / recovery cost | $ | Scrap, cleaning and recovery cost to restart |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Downtime
- What it is
- How long the stoppage lasted, or is expected to last, from the stop to the return of normal production.
- Units and format
- Enter a number in hr: hours. The form accepts 0 hr or more.
- Example
- The form opens with 6 hr as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Lost contribution and idle labour rise in proportion.
- Get it right
- Enter hours: 45 minutes is 0.75 hours.
What this means: Lost contribution / operating hour
- What it is
- The margin lost for each hour the line is not producing: sales value of the missed output minus its variable cost.
- Units and format
- Enter a number in $/hr: money per hour. The form accepts $0/hr or more.
- Example
- The form opens with $800/hr as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Lost contribution is hours × this figure.
- Get it right
- If the output is made up later on overtime, the real loss is the overtime cost, not this contribution.
What this means: People affected
- What it is
- The number of people paid during the stoppage who cannot do productive work because of it.
- Units and format
- Enter a number in people: people. The form accepts 0 people or more.
- Example
- The form opens with 4 people as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Idle labour cost rises in proportion.
- Get it right
- Leave out people moved to other useful work during the stop.
What this means: Loaded labour rate
- What it is
- The full hourly cost of one affected person: wages plus on-costs such as superannuation, leave and payroll tax.
- Units and format
- Enter a number in $/hr: money per hour. The form accepts $0/hr or more.
- Example
- The form opens with $50/hr as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Idle labour cost rises in proportion.
- Get it right
- Do not include labour here if the contribution figure already counts it.
What this means: Restart / recovery cost
- What it is
- One-off costs to get running again after the stop: scrapped start-up parts, cleaning, re-qualification and call-out charges.
- Units and format
- Enter a number in $: an amount of money; use one currency for every money input. The form accepts $0 or more.
- Example
- The form opens with $600 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Added once to the total cost.
- Get it right
- Enter the total for this stoppage, not a rate per hour.
Method and formulas
- Lost contribution = hours × contribution per hour
- Idle labour = hours × people × rate
- Total = lost contribution + idle labour + restart
Limitations
- If output is recovered later, lost contribution is overstated
Typical uses
- Ranking maintenance improvements
- Justifying critical spares
Who it is for
- Maintenance and operations managers
What you get
- Total downtime cost and cost per hour
- Cost composition
Interpreting the result
- Use cost per downtime hour to rank preventive actions
Learn the Concepts Behind This Tool
These BIZOMAT Library readings explain the method this tool uses, with worked examples.
Method explained here · BIZOMAT original book
From model to decision: what to fix first
In Breakdowns and Buffers by the Numbers
What it covers: Pricing a minute of downtime, ranking improvements by the output they add on a buffered line, wear-out parts on a schedule, checking predictions against results, and the Pareto chart that misled.
Method explained here · BIZOMAT original book
Short exposure windows: installing in days, not weeks
In Modular Projects by the Numbers
What it covers: Disruption risk grows with days on site: 69.9% over 15 days against 21.3% over 3, A$228,000 against A$58,600 of site-related cost per cell, and a permit day nobody planned.
Method explained here · Library collection
Putting a dollar value on equipment losses: using OEE to guide capacity and capital decisions
In Valuing Time, Delay and Uncertainty
What it covers: An OEE percentage shows capacity is being lost, not what the loss is worth. How to value downtime, speed and quality losses, focus on the constraint and check before buying equipment.
Useful alongside · BIZOMAT original book
Backups you have actually restored
What it covers: Set recovery point and recovery time objectives for a CAD vault, back up its database and file archive at one consistent point, and prove recovery with a timed test restore.
BIZOMAT tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.