Time Study Calculator

Determine required sample size and analyze time observations with outlier detection

Time Study Analysis

Time study is a work measurement technique for recording the times of performing a task's elements, with the objective of determining the time required at a defined level of performance.

Normal Time = (Average Observed Time) × (Performance Rating)
Standard Time = Normal Time × (1 + Allowance Factor)

Key steps:

  1. Conduct a pilot study
  2. Calculate the sample size based on the pilot data
  3. Record observed times
  4. Check for and remove outliers
  5. Calculate normal and standard times
1. Sample Size
2. Time Study

Determine Required Sample Size

Calculate the number of observations needed for a desired confidence level and accuracy.

Sample Size Results

Pilot study distribution will appear here

Time Study Analysis

Analyze your time observations, detect outliers, and calculate normal and standard times.

Time Study Results

Time study distribution will appear here
Observation Time Status

Performance Calculations

Normal Time

Average Time × Performance Rating

Standard Time

Normal Time × (1 + Allowance Factor)

Practical Examples

Example 1: Sample Size Determination

Pilot Times: 12.5, 13.2, 11.8, 12.9, 12.3

Confidence: 95% | Accuracy: ±5%

Mean: 12.54 | Std Dev: 0.52 | Required Samples: 11

Example 2: Time Study Analysis

Observed Times: 12.5, 13.2, 11.8, 12.9, 12.3, 15.7, 12.1

Performance Rating: 110% | Allowance: 15%

Outlier: 15.7 (IQR method) | Normal Time: 13.75 | Standard Time: 15.81

Recommended Resources

Accurate time study requires the right mix of knowledge, tools, and practice. Here are some of my handpicked resources:

📚 Classic Reference: Ralph Barnes

"Motion and Time Study" by Ralph M. Barnes is a foundational book in work measurement and methods improvement.

View on Amazon

⏱️ Stopwatch for Time Studies

A digital stopwatch with split/lap memory functions is ideal for conducting professional time studies in any working environments.

Browse Options

Disclosure: As an Amazon Associate I earn from qualifying purchases. These are resources we genuinely recommend for conducting time studies.

Time Study Methods

Method Description When to Use
Continuous Timing Recording all elements continuously with a stopwatch Short cycles, high accuracy needed
Snapback Timing Stopwatch is reset after each element Long cycles, distinct elements
Work Sampling Random observations to determine time proportions Long, irregular cycles
Predetermined Time Systems Using standard time data for basic motions When direct measurement isn't possible