At SRCN, we do not rely on wrench time or time in motion studies to justify change. Not because we think efficiency does not matter, but because the best improvements are usually visible and provable through flow, readiness, and schedule stability. These measures point to system issues, not effort issues, and they give leaders a much cleaner case for action.
This, the final article in the series, is about how to build that case.
Start with a different question
Instead of asking:
“How busy are our people?”
ask:
“Are we reliably converting demand into completed, high-value work?”
That is what organisations and leaders actually care about: safety, reliability, cost, and delivery. You only get those outcomes when work flows through the system without bottlenecks, rework, and constant priority churn.
Three measures that unlock the case for change
1. Workflow Measures
Workflow is how smoothly work moves from identified, to validated, to prepared, to scheduled, executed, and closed out.
Whilst a considerable amount of complexity can be introduced when looking to measure workflow, it is possible to glean considerable insight without getting overly complicated. A small number of signals can be used to show whether work is moving or stuck.
Examples of useful flow signals include:
- Backlog growth rate and backlog age profile by priority or criticality
- Work in progress. i.e. how many jobs are started but not yet finished
- Volume and time spent in key process stages. e.g., waiting for validation, waiting for preparation, waiting for materials, waiting for close out
- Rework and restart frequency, how often jobs are paused, returned, or rescheduled
What these can show:
- The system is overloading itself with too much work in progress
- Work is entering execution without being truly ready
- Constraints such as materials, permits, isolations, and access are not being managed early
enough
Close-outs are poor, so learning and data quality degrade, which increases future waste
Using these metrics, focus improvements can be justified in the following ways:
- If backlog grows while the workforce is flat out, the problem is demand control and execution efficacy, not effort
- If the work in progress is high, there is a strong justification for reducing the volume of scheduled work to reduce work in progress, a need for better preparation, increased focus on being ready to execute assurance and a conscious effort to deliver more stable scheduling
- If waiting times are long at any stage, then a specific intervention, added capacity or clearer decision rights in the specific stage that is the constraint can all be justified
2. Readiness
Readiness and its effectiveness are the most powerful alternatives to wrench time because they show whether the organisation is setting the workforce up to succeed.
Readiness answers one simple question:
“When we schedule work, is it genuinely ready to execute?”
Readiness signals:
- Percentage of scheduled work that meets an organisation’s “Ready to Execute” standard at schedule freeze
- Reasons work is not ready, missing parts, missing isolations, incomplete scope, missing access, missing vendor support, missing risk controls
- Jobs that change after start, additional materials requests, additional isolations, scope rework, job pack rework
What it tells you:
- Planning is being treated as paperwork, not risk removal
- Materials and access issues are being discovered too late, as work preparation is happening too late
- There is weak gating, meaning unready work is pushed into the week and then fails in execution
How to justify improvements from readiness:
Readiness gives you a very defensible business case because it links directly to lost time and risk without blaming technicians.
- If readiness at freeze is low, you can justify investment in preparation, materials discipline, and earlier constraint removal
- If jobs frequently change after start, you can justify raising the minimum standard of preparation and enforcing a real readiness gate
If the same readiness failures repeat, you can justify targeted fixes in the upstream process, such as scope quality, validation discipline, or materials workflows
3. Schedule stability
Schedule stability is where leaders see the value immediately because it connects to delivery, trust, and firefighting. The two key things to focus on are:
- Schedule attainment: Did you complete what you said you would complete?
- Schedule compliance: Did you execute the schedule as planned, with minimal break-ins and churn?
Schedule stability signals are:
Schedule attainment each week
Break-ins, number, size, and reason codes
Volume of schedule changes after freeze
Percentage of executed work that was planned versus unplanned
These measures tell you if the week is being built on assumptions instead of readiness. They will also show if priorities are changing because decision rights are unclear or governance is weak, and whether there is sufficient buffer for normal variability, so small issues don’t cascade into major disruption.
Improvements can be justified from schedule stability based on the following:
If attainment is low, you can justify a readiness standard and a stronger freeze discipline
If break-ins are high, you can justify better triage, clearer definitions of what qualifies as a true break-in, and stronger protection of the weekly plan
If the schedule changes constantly, you can justify a governance reset, including decision rights and escalation rules
How to turn these measures into a practical improvement case
Step 1: Describe the operational symptoms, not the blame story
There is often the temptation to justify the performance or assign blame. It is far more
productive to use neutral language that focuses on system behaviour.
- The backlog is growing and ageing
- The plan changes daily
- Jobs frequently stop and restart
- Work scope changes after mobilisation
This keeps the conversation constructive and avoids the workforce feeling unjustifiably targeted.
Step 2: Quantify the cost of instability
Quantifying cost does not require a stopwatch. Use visible consequences:
- Number of break-ins per week and their drivers
- Percentage of scheduled work that was notready
- Number of jobs that required additional materials or isolations after start
- Average queue time in preparation or materials status
These translate directly into lost throughput and increased risk.
Step 3: Link each symptom to a specific new control
This is really the lynchpin of the justification as it makes it explicit how the symptoms will
be rectified.
Example mapping:
- Low schedule attainment links to readiness at freeze and break in control
- High work in progress links to work-in-progress limits and better weekly planning discipline
- Frequent job changes are linked to improved preparation standards and earlier constraint removal
- Backlog growth links to demand control, prioritisation discipline, and realistic capacity planning
Step 4. Propose fixes as controls and standards, not headcount asks
Leaders often jump straight to, " We need more people". Your measures help you avoid that trap.
A strong improvement proposal usually includes:
- A clear Ready to Execute definition and a measurable readiness gate
- A frozen weekly schedule discipline with agreed break-in rules
- Better validation and prioritisation governance, including decision rights
- Focused improvement on the constraint stage, usually preparation, materials, or isolations
- Simple leading indicators, reviewed weekly, not quarterly lagging metrics
Step 5. Define what success looks like in weeks, not years
Pick a small set of targets that show the system is becoming stable.
- Readiness at freeze improves
- Break-ins reduce and become truly exceptional
- Schedule attainment rises
- Work in progress reduces and completion increases
Backlog stops growing and begins to de-age
That is a far more compelling story than “we increased wrench time”, as it will show that the intentions are being achieved, not simply that people are getting more done.
Closing thought
Wrench time measures effort. Workflow, readiness, and schedule stability measure whether the organisation is creating the conditions for productive work.
If you want higher output and better control, measure the system, not the people.
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