Category
Industrial Engineering
Industrial engineering formulas and calculators for operations research, quality control, and process optimization used to improve production efficiency. Includes queuing theory, inventory management, and SPC equations.
30Formulas
2Subcategories
Updated Jul 2026
General
SMED Setup Time Reduction Ratio
Reduction (%) = ((Old Setup Time - New Setup Time) / Old Setup Time) * 100
General
Total Float (Project Scheduling)
TF = Late Start - Early Start
General
Project Crash Cost per Day
Crash Cost/Day = (Crash Cost - Normal Cost) / (Normal Time - Crash Time)
General
Standard Time (With Allowances)
ST = Normal Time * (1 + Allowance Factor)
General
Learning Curve Time Reduction
T_n = T_1 * n^(log2(LR))
Quality Control
Failure Rate
λ = 1 / MTBF
Quality Control
System Availability (Reliability Engineering)
Availability (%) = (MTBF / (MTBF + MTTR)) * 100
Quality Control
Mean Time To Repair (MTTR)
MTTR = Total Repair Time / Number of Repairs
Quality Control
Mean Time Between Failures (MTBF)
MTBF = Total Operating Time / Number of Failures
Quality Control
Rolled Throughput Yield
RTY = Y1 * Y2 * Y3 * ... * Yn
Quality Control
First Pass Yield
FPY (%) = (Units Passing Without Rework / Total Units Started) * 100
Quality Control
Process Capability Index (Cpk, Accounting for Centering)
Cpk = min[(USL - μ)/(3σ), (μ - LSL)/(3σ)]
Quality Control
X-bar Control Chart Limits
UCL/LCL = X̄̄ ± A2 * R̄
Quality Control
Defects Per Million Opportunities (DPMO)
DPMO = (Number of Defects / (Units * Opportunities per Unit)) * 1,000,000
Quality Control
Six Sigma Process Sigma Level
Sigma Level ≈ 0.8406 + sqrt(29.37 - 2.221*ln(DPMO))
Operations Research
Inventory Turnover Ratio (Manufacturing)
Turnover = Cost of Goods Sold / Average Inventory Value
Operations Research
Production Throughput Rate
Throughput = Units Produced / Time Period
Operations Research
Assembly Line Balancing Efficiency
Efficiency (%) = (Sum of Task Times / (Number of Stations * Cycle Time)) * 100
Operations Research
Manufacturing Cycle Time
Cycle Time = Total Production Time / Units Produced
Operations Research
Takt Time
Takt Time = Available Production Time / Customer Demand
Operations Research
Average Wait Time in System (M/M/1)
W = 1 / (μ - λ)
Operations Research
Average Number in Queue (M/M/1)
Lq = ρ² / (1 - ρ)
Operations Research
Traffic Intensity (M/M/1 Queue Utilization)
ρ = λ / μ
Operations Research
Newsvendor Critical Ratio
CR = Cu / (Cu + Co)
Operations Research
Safety Stock (Variable Demand and Lead Time)
SS = Z * sqrt(LT * σd² + d² * σLT²)
Operations Research
Reorder Point
ROP = (Average Daily Demand * Lead Time) + Safety Stock
Quality Control
Overall Equipment Effectiveness
OEE = Availability × Performance × Quality
Quality Control
Process Capability Index
C_p = (USL − LSL) / (6σ)
Operations Research
Little's Law
L = λW
Operations Research
Economic Order Quantity
EOQ = √(2DS / H)