What is the difference between starved and blocked?

Starved means the station is ready but no part is coming in; blocked means it holds a finished part and has nowhere to send it. Starving points upstream and blocking points downstream, so this calculator keeps them apart.

Does starved or blocked time at a non-constraint station matter?

Less than at the constraint. A station faster than the constraint has to wait some of the time, so part of its starved and blocked time is normal. At the constraint, every lost minute is lost line output.

Where should the buffers go?

Ahead of and behind the constraint. Keep the upstream conveyor full so the constraint is never starved, and the downstream conveyor empty so it is never blocked. Machines farther from the constraint run faster to refill and clear them.

Does starved and blocked time count as downtime in OEE?

Yes, above your reason-code cutoff: OEE.com lists being starved by upstream equipment or blocked by downstream equipment among unplanned stops, an availability loss. Shorter waits are minor stops, a performance loss. Code them apart from breakdowns so the fix goes to line flow, not maintenance.

Conveyors calculator

Starved and Blocked Time Calculator

Split a station's lost flow time into starved and blocked, check the total against your limit, and see which side of the line to fix. You need PLC state timers or a timed study.

What this calculator does

Share of a station's observed time lost to starving and blocking, checked against your limit, with the output lost at the constraint.

Formula used

Starved share = starved minutes ÷ observed minutes × 100
Blocked share = blocked minutes ÷ observed minutes × 100
Starved and blocked share = starved share + blocked share
Margin to limit (points) = flow loss limit − starved and blocked share
Output lost at the constraint = (starved + blocked minutes) ÷ 60 × station rate (units / hr)

Inputs explained

Starved Minutes: Minutes the station waited for parts, from its PLC state timer.
Blocked Minutes: Minutes the station held a finished part with nowhere to send it.
Observed Minutes: Production minutes in the same study window, breaks excluded.
Flow Loss Limit: Your maximum starved plus blocked share, from the line target.
Station Rate When Running: Units per hour this station makes while running, from its counter.

How to use the result

Best suited to placing buffers around a constraint machine, proving a line balancing change worked.
Output lost applies only when this station is the constraint; a faster station's waiting costs no output. Does not say which neighbor caused the loss; log upstream and downstream states to trace it.

Current U.S. benchmarks

The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

What is the difference between starved and blocked? Starved means the station is ready but no part is coming in; blocked means it holds a finished part and has nowhere to send it. Starving points upstream and blocking points downstream, so this calculator keeps them apart.
Does starved or blocked time at a non-constraint station matter? Less than at the constraint. A station faster than the constraint has to wait some of the time, so part of its starved and blocked time is normal. At the constraint, every lost minute is lost line output.
Where should the buffers go? Ahead of and behind the constraint. Keep the upstream conveyor full so the constraint is never starved, and the downstream conveyor empty so it is never blocked. Machines farther from the constraint run faster to refill and clear them.
Does starved and blocked time count as downtime in OEE? Yes, above your reason-code cutoff: OEE.com lists being starved by upstream equipment or blocked by downstream equipment among unplanned stops, an availability loss. Shorter waits are minor stops, a performance loss. Code them apart from breakdowns so the fix goes to line flow, not maintenance.

Last reviewed 2026-10-01.