Operations Research

Operations research calculators and formulas for inventory, queuing, and optimization models. Covers economic order quantity, queue length, and linear programming calculations.

13Formulas

All levels Difficulty

Updated Jul 2026

← All Industrial Engineering (30) Operations Research (13)

Fundamental

Inventory Turnover Ratio (Manufacturing)

Turnover = Cost of Goods Sold / Average Inventory Value

Fundamental

Production Throughput Rate

Throughput = Units Produced / Time Period

Fundamental

Assembly Line Balancing Efficiency

Efficiency (%) = (Sum of Task Times / (Number of Stations * Cycle Time)) * 100

Fundamental

Manufacturing Cycle Time

Cycle Time = Total Production Time / Units Produced

Fundamental

Takt Time

Takt Time = Available Production Time / Customer Demand

Fundamental

Average Wait Time in System (M/M/1)

W = 1 / (μ - λ)

Fundamental

Average Number in Queue (M/M/1)

Lq = ρ² / (1 - ρ)

Fundamental

Traffic Intensity (M/M/1 Queue Utilization)

ρ = λ / μ

Fundamental

Newsvendor Critical Ratio

CR = Cu / (Cu + Co)

Fundamental

Safety Stock (Variable Demand and Lead Time)

SS = Z * sqrt(LT * σd² + d² * σLT²)

Fundamental

Reorder Point

ROP = (Average Daily Demand * Lead Time) + Safety Stock

Fundamental

Little's Law

L = λW

Fundamental

Economic Order Quantity

EOQ = √(2DS / H)