Work-in-progress piles up between stages
Count unfinished pieces waiting between each operation at a fixed time. Use what you find to change the way this work is handled this week.
The production supervisor usually hears about this through a phone call or a last-minute request. Half-finished parts sit between operations and hide the real bottleneck. A usable fix starts with evidence and one person accountable for the next decision.
What it looks like
- The production supervisor has to search the current job cards and machine schedule before answering a routine question.
- Half-finished parts sit between operations and hide the real bottleneck.
- Staff cannot locate a released job card and actual output entry for the latest case.
- People spot the gap after one machine works on the wrong priority while a customer order waits.
- The open case has no documented owner, due date or proof of closure.
Why it happens
The specific failure is left unchecked. Half-finished parts sit between operations and hide the real bottleneck. If there is no recorded owner for that condition, the effect travels to the next team.
The work and its evidence move separately. The planned queue is changed before checking the operation that will actually carry the work.
A later hand-off exposes the gap. Material readiness, machine time, tooling and inspection capacity are often reviewed in separate places.
The less obvious cause: A control may exist on paper but still fail in practice. Test whether someone actually performs this check: compare daily input and output at the longest queue.
Find the first failed hand-off before changing staff targets. A completed register alone cannot prove that physical work happened.
What to check first
- Count unfinished pieces waiting between each operation at a fixed time. Compare dates, quantities and references. Mark an unconfirmed difference as unverified. Finish the first pass in under 30 minutes and name the missing source if needed.
- Compare daily input and output at the longest queue. Record the affected item or party and the person who can verify the detail. Finish the first pass in under 30 minutes and name the missing source if needed.
- Check whether batches are released faster than the next stage can process. Mark each exception open, waiting for evidence or resolved, with a named next owner. Finish the first pass in under 30 minutes and name the missing source if needed.
How to fix it
- Start with one live case. Count unfinished pieces waiting between each operation at a fixed time. Keep the source reference before changing the record.
- Make the control explicit. Limit new release into an overloaded stage. Put the rule in the register or sheet that staff already use.
- Set a second guardrail. Review age and quantity of work-in-progress daily. Separate firm work from tentative requests. A job is ready only when its tools, material, people, specification and capacity are actually available.
- Assign the next decision. The production supervisor records the action and its due date. A separately authorised person signs off changes affecting money, safety or customer terms.
- Review the open list. Start with items affecting today or tomorrow. Keep third-party commitments separate from completed actions.
- Check whether the rule holds. For four weeks, count jobs blocked at the next operation or pushed beyond their committed dates. Reopen repeat cases and identify where the control failed.
Copy this daily production risk sheet into a register or sheet:
| Reference / item | What went wrong | Evidence checked | Action owner | Promised date | Status / decision |
|---|---|---|---|---|---|
| P045 (example) | wip piles up | Count unfinished pieces waiting between each operation at a fixed | Production supervisor | Set at review | Open |
Retain the source reference and limit access to authorised staff.
A worked example
Illustrative example only. A casting unit has 2,400 pieces waiting for fettling while moulding keeps producing. Start by locating the source that would verify these amounts or quantities. The production supervisor records the exact exception, gives it an owner and checks the next relevant event. This example shows how to structure the decision. It does not claim that a business achieved a saving or avoided a loss.
How you know it is fixed
- Completeness: Count jobs blocked at the next operation or pushed beyond their committed dates at the same time every week. Record the count and the oldest item, rather than just saying things are better.
- Timeliness: Check whether the assigned person took the next action before the agreed cut-off. Keep missed dates visible instead of replacing them silently.
- Proof of closure: Sample three closed cases and locate a released job card and actual output entry. A tick without supporting evidence is still an open control gap.
When it is more serious
Old WIP may hide defects, deterioration or wrong revisions. Stop affected work and seek a competent technical or safety review if the case can harm people or release unsafe goods. For contracts, tax, wages or legal rights, retain source documents and consult a qualified adviser. Repeated exceptions after four reviews may require changing the control.
This works if someone does it every day. In most businesses, that someone is you.
Questions people ask
What should we check before taking action?
Count unfinished pieces waiting between each operation at a fixed time. Keep its date and reference. Then compare it with a released job card and actual output entry; if they disagree, record the difference before changing either one.
Who should own the next action?
The production supervisor should own the open item. The person authorised to change money, a technical standard or a customer commitment must still approve that decision.
Can we run this control without new software?
No. Start with a shared sheet or register containing the reference, owner, promised date, status and evidence. Once those fields are reliable, decide whether a system connection is worth setting up.
When is the issue serious enough to escalate?
Old WIP may hide defects, deterioration or wrong revisions. Keep supporting records and get specialist help where relevant.