BIZOMAT Tools · Improvement
Before and After Comparison
Did the change actually improve the process?
Compares cycle time, unit cost and defect rate before and after a change and flags mixed results.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Before cycle time | min | Measured cycle time before |
| After cycle time | min | Measured cycle time after |
| Before cost / unit | $ | Unit cost before |
| After cost / unit | $ | Unit cost after |
| Before defect rate | % | Defect rate before |
| After defect rate | % | Defect rate after |
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: Before cycle time
- What it is
- The cycle time for one unit before the change, measured over a representative run.
- Units and format
- Enter a number in min: minutes. The form accepts 0 min or more.
- Example
- The form opens with 10 min as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The time change is worked out as a percentage of this before value.
- Get it right
- Measure before and after the same way, over similar volumes and product mix.
What this means: After cycle time
- What it is
- The cycle time for one unit after the change, measured the same way as the before value.
- Units and format
- Enter a number in min: minutes. The form accepts 0 min or more.
- Example
- The form opens with 8 min as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A shorter after time counts as an improvement.
- Get it right
- Wait until the new method has settled in before measuring.
What this means: Before cost / unit
- What it is
- What one unit cost to produce before the change, on your normal costing basis.
- 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 $10 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The cost change is worked out as a percentage of this before value.
- Get it right
- Use the same cost elements before and after, for example both including overhead.
What this means: After cost / unit
- What it is
- What one unit costs to produce after the change, on the same costing basis as before.
- 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 $8.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A lower after cost counts as an improvement.
- Get it right
- Include any new running costs the change brings, such as consumables or licences.
What this means: Before defect rate
- What it is
- The share of units found defective before the change, from inspection or quality records.
- Units and format
- Enter a number in %: percent: the number is read as a percentage, so type 8 for 8 %. The form accepts 0% to 100%.
- Example
- The form opens with 4% as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The defect change is before minus after, in percentage points.
- Get it right
- Type the percentage (4 for 4 %), not a fraction.
What this means: After defect rate
- What it is
- The share of units found defective after the change, measured with the same inspection method as before.
- Units and format
- Enter a number in %: percent: the number is read as a percentage, so type 8 for 8 %. The form accepts 0% to 100%.
- Example
- The form opens with 2% as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A lower after rate counts as an improvement.
- Get it right
- Small samples can show large swings; use a period long enough to be meaningful.
Method and formulas
- Percentage change = (before − after) ÷ before
- Defect change in percentage points
Limitations
- No statistical test; small samples may mislead
Typical uses
- Confirming an improvement
- Reporting project results
Who it is for
- Improvement teams
- Managers reviewing results
What you get
- IMPROVED, MIXED RESULT, UNCHANGED or WORSE
- Change table
Interpreting the result
- A mixed result needs investigation before standardising
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.