# Overall Equipment Effectiveness (OEE) & TEEP Sizing Methodology for API Pharma & Fine Chemical Manufacturing

# 1. Overview & Theoretical Principles

Overall Equipment Effectiveness (OEE) and Total Effective Equipment Performance (TEEP) are the global benchmarks for quantifying asset utilization, equipment availability, operational velocity, and batch yield performance across API synthesis plants, isolation suites, drying units, solvent recovery columns, and formulation suites.

In pharmaceutical batch manufacturing, OEE evaluates the fraction of planned production time that is truly productive by incorporating three core performance pillars:

While OEE measures efficiency during Planned Production Time, TEEP measures overall equipment performance against Total Available Calendar Time (24 hours/day, 365 days/year = 8,760 hours/yr):

Where:

World-Class OEE performance target for pharmaceutical batch synthesis is $\ge 85.0\%$ ($\text{Availability} \ge 90\%$, $\text{Performance} \ge 95\%$, $\text{Quality} \ge 99.9\%$).

# 2. Mathematical Framework & Equations

# 2.1 Availability Rate ($A$)

Where:

• $T_{\text{planned}} = T_{\text{shift}} - (T_{\text{PM}} + T_{\text{CIP/SIP}} + T_{\text{swab hold}})$
• $T_{\text{unplanned}} = T_{\text{mechanical}} + T_{\text{utility outage}} + T_{\text{process delay}}$

# Pharma Downtime Classifications:

1. Planned Maintenance & Calibration ($T_{\text{PM}}$): Scheduled instrument calibration, pressure vessel inspection, lubrication.
2. CIP / SIP / Boil-out ($T_{\text{CIP/SIP}}$): Sanitary cleaning-in-place, steam-in-place sterilization, solvent boil-out wash cycles between batches or product campaigns.
3. QA Swab & Validation Clearance ($T_{\text{swab hold}}$): Holding time waiting for QC laboratory swab testing, TOC analysis, and QA batch record release.
4. Mechanical Breakdowns ($T_{\text{mechanical}}$): Agitator mechanical seal failures, glass-lining damage, pump impeller seizures, valve body leaks.
5. Utility Outages ($T_{\text{utility outage}}$): Nitrogen header pressure drops, chilled glycol/brine temperature trips, high-pressure steam supply failure, vacuum system pull-down failures.

# 2.2 Performance Rate ($P$)

Where:

• $t_{\text{recipe, ideal}}$ = Validated nameplate design recipe cycle time ($\text{minutes}$ or $\text{hours}$)
• $N_{\text{batch}}$ = Number of batches processed during the shift
• $T_{\text{operating}}$ = Actual measured machine operating time

# Speed & Cycle Drag Losses ($T_{\text{speed loss}}$):

Causes include heat exchanger jacket fouling slowing reaction heating/cooling ramp rates, agitation RPM restrictions due to slurry viscosity, or low vacuum levels extending distillation/drying cycles.

# 2.3 Quality Rate ($Q$) & Chemical Yield Efficiency

Where:

• $N_{\text{rejected}}$ = Out-of-specification (OOS) batches destroyed or discarded as scrap
• $N_{\text{reworked}}$ = Off-spec batches requiring reprocessing, re-crystallization, or re-distillation
• $Y_{\text{actual}}$ = Actual achieved molar or mass product yield ($\%$)
• $Y_{\text{target}}$ = Validated standard target recipe yield ($\%$)

# 2.4 Reliability Metrics (MTBF & MTTR)

# 3. The 6 Big Losses Framework in API Pharma Manufacturing

1. Mechanical Equipment Breakdowns: Agitator mechanical seal failures, vacuum pump seal burnouts, transfer pump trips.
2. Setup, CIP/SIP & QA Swab Validation: Sanitary cleaning washouts, campaign changeover, waiting for QC lab swab release.
3. Utility Outages & Minor Stoppages: Chilled brine temperature spikes, steam pressure drops, nitrogen blanketing pressure alarms.
4. Reduced Speed / Heat Transfer Fouling: Extended batch reaction/drying cycle times caused by fouled reactor jackets, low agitator RPM, or vacuum leaks.
5. Production Rejects & Off-Spec Batches: Batches failing assay, HPLC impurity profile, or dissolution testing requiring complete scrap.
6. Chemical Yield & Startup Scrap: Solvated product left in mother liquors, filtration cake holdup losses, startup fraction cuts during distillation.

# 4. Industry Equipment Presets & Governing Standards

# Preset Equipment Profiles Included:

• 5,000 L GLR Synthesis Reactor: Multi-step batch synthesis (Charging, Reaction, Distillation, Crystallization, CIP & Swab Hold).
• 3 m² ANFD Filter Dryer: Slurry filtration, washing, deliquoring, vacuum drying & discharge.
• 2,000 L RCVD Vacuum Dryer: Rotary cone vacuum drying cycle under heat ramp & vacuum release.
• Solvent Recovery Distillation Column: Continuous/semi-batch column running multi-day recovery campaigns.
• Solid Oral Tablet Packaging Suite: High-speed compression press & blister packaging.

# Governing Standards:

• ISO 22400-2:2014: Automation systems and integration — KPIs for manufacturing operations management.
• ISPE Baseline Guide: Volume 3 — Sterile Product Manufacturing Facilities & Cleanroom Operations.
• TPM (Total Productive Maintenance): Japan Institute of Plant Maintenance (JIPM) framework.