maji Framework

The Time Hierarchy

Every hour your factory loses has a cause and a cost. This framework makes both visible.

The Problem with OEE

Traditional OEE (Overall Equipment Effectiveness) multiplies Availability × Performance × Quality into a single percentage. This has three problems:

  • It obscures magnitude. A line at 65% OEE could have a 30% downtime problem and negligible quality losses, or moderate losses across all three. You cannot tell which from the number alone.
  • It double-counts. Speed losses on waste units are counted in both Performance and Quality. The multiplicative structure makes this unavoidable.
  • It cannot be valued in pounds. A percentage does not tell you what an improvement is worth. Time does — every lost hour has a financial value that depends on your constraint state.
  • It cannot be summed across products. You cannot add OEE percentages from different SKU runs to get a meaningful total. Time-based measurement can: sum Potential Time and Actual Operating Time across any number of products (provided each has a SKU-specific bottleneck speed) and the ratio remains valid.

Time-based additive decomposition expresses every loss as a duration. Losses are directly comparable, mutually exclusive, summable across products, and convertible to financial impact.

How It Works

Calendar Time is all time that exists. Through a series of subtractions — non-working time, schedule losses, planned downtime, unplanned downtime, speed losses, and quality losses — we arrive at Potential Time: the theoretical minimum time needed to produce your actual good output at maximum bottleneck speed.

Everything between Calendar Time and Potential Time is a loss. The hierarchy classifies every loss into a mutually exclusive category so nothing is double-counted and every loss can be valued.

Key principle: The hierarchy is measured at the bottleneck — the process step that limits throughput. Non-bottleneck steps have excess capacity and are not the constraint.

Interactive Time Hierarchy

Click any block with a + icon to expand and reveal nested levels. Use the "Show Me" buttons below to highlight how each efficiency metric is constructed.

Calendar Time
Productive Time
Subtracted / Loss
Speed / Quality Loss
Non-working Time
SUBTRACTED
Subtracted from Calendar Time to define Shift Time, but remains a loss when measuring Total Effective Equipment Performance (in production-constrained environments only)
• Weekends
• Night shifts (if not operating)
• Holidays
Schedule Loss
SUBTRACTED
Subtracted from Shift Time to define Planned Production Time, but remains a loss when measuring Machine Efficiency / Overall Operations Effectiveness (equipment not producing)
• Paid breaks and meal periods
• Scheduled maintenance windows during operational hours
• Periods with no customer demand during scheduled time
Planned Downtime
SUBTRACTED
Subtracted from Planned Production Time to define Operating Time, but remains a loss when measuring Overall Equipment Effectiveness (equipment not producing)
• Changeovers
• Planned maintenance
• Start-of-shift checks
Unplanned Downtime
LOSS
Stops exceeding classification threshold, Planned Downtime overruns, Schedule Loss overruns
Lost Time Slow Running
LOSS
Production below bottleneck speed — includes micro-stops and speed losses
Lost Time Making Waste
LOSS
Time spent producing defective output
Potential Time
Good output at bottleneck speed — theoretical minimum time required

Which Metrics Matter to You?

Before choosing a metric, identify your constraint state: can you sell more if you made more? Each metric widens the denominator one level up the hierarchy.

AudienceMetricFormulaLosses in scope
Shop Floor Operating Efficiency PT / Operating Time UPDT, LTSR, LTMW
Operations OEE PT / PPT Adds PDT
Management OOE / Machine Efficiency PT / Shift Time Adds Schedule Loss
Strategic TEEP PT / Calendar Time Adds Non-working Time
Strategic Output per Labour Hour Good Output / Labour Hrs Sales-constrained only

Machine Efficiency and OOE are the same formula (PT / Shift Time) — the name changes with strategic intent. OEE in majaco’s framework = PT / PPT (the additive equivalent of the traditional Availability × Performance × Quality). For full formula derivations and the acronym glossary, see the Efficiency Formulas reference.

The Metrics

Click “Show Me” to highlight the numerator (PT) and denominator in the cascade above.

Operating Efficiency = PT / Operating Time

Shop floor metric. UPDT, LTSR, and LTMW are in scope. Schedule Loss and PDT are not (planning decisions). World-class: ≥85%.

OEE = PT / PPT

Operations metric. Adds PDT to scope — holds the team accountable for changeover time and planned maintenance efficiency. Since PT = Good Output / BNS, this equals Good Output / (PPT × BNS) = Good Output / Potential Output. This is the additive equivalent of the traditional A × P × Q, without double-counting speed losses on waste.

OOE (Machine Efficiency) = PT / Shift Time

Management metric. Adds Schedule Loss — how well the operation uses all available shift hours. Same formula, different name: “Machine Efficiency” in sales-constrained contexts, “OOE” in production-constrained.

TEEP = PT / Calendar Time

Strategic metric for production-constrained environments. Total asset utilisation including non-working time. Answers: “how much of the factory’s theoretical capacity are we using?”

Output per Labour Hour = Good Output / Total Labour Hours

Strategic metric for sales-constrained environments. Improving OOE or optimising crew size both increase this metric, reducing cost per unit.

Numerator — PT (in cascade)
Denominator (in cascade)

From Time to Money

The framework’s payoff: every lost hour has a pound value.

Production-Constrained
Lost Time × BNS × UMP = opportunity value.
Every recovered hour produces additional saleable output.
Sales-Constrained
Labour Hours Saved × Fully Loaded Labour Cost = opportunity value.
Recovered time enables fewer people or fewer hours for the same output.

The difference matters enormously. The same 2.5 hours of UPDT per day can be worth £5.4M/yr (production-constrained, valued at throughput margin) or £82k/yr (sales-constrained, valued at labour cost saved) — a 66× difference. Getting the constraint diagnosis right is not optional.

Formulas & Glossary

All formulas, acronym definitions, the OEE equivalence proof, and diagnostic quick-reference are on the dedicated reference page:

Efficiency Formulas Quick Reference →

See what your lost time is costing you

majaco can implement this framework in your facility — from data collection design through to live dashboards and financial valuation.

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