Lesson 9.1: Work Study & Time-Motion Analysis

Work study and time-motion analysis are key topics in Industrial Engineering. GATE and PSU exams often test efficiency improvement, standard time calculation, and process optimization.

🔹 1. Introduction

• Definition:

  • Work Study: Systematic method to improve efficiency by analyzing work methods and measuring time.

  • Time-Motion Study: Detailed study of time required for tasks and movements.

• Applications: Manufacturing units, assembly lines, process optimization

• Key Concepts: Method study, micro-motion study, standard time, performance rating

🔹 2. Work Study

• Objectives:

  1. Eliminate unnecessary operations

  2. Reduce fatigue and increase productivity

  3. Standardize best practices

• Components:

  • Method Study: Analyze and improve method of doing work

  • Work Measurement: Determine time required to complete a task

• Tools: Process charts, operation charts, flow diagrams, chronocyclegraph

🔹 3. Time-Motion Analysis

• Definition: Study of time and motions for efficient work execution

• Techniques:

  1. Time Study (Stopwatch Method): Measures time for each task

  2. Predetermined Motion Time Systems (PMTS): Uses standard data for motions

  3. Micro-Motion Study: Detailed analysis using therbligs

• Objectives:

  • Set standard time

  • Identify wasteful motions

  • Improve worker productivity

🔹 4. Performance Rating & Allowances

• Performance Rating: Adjust observed time for worker efficiency

• Standard Time Calculation:

$$StandardTime=NormalTime\times (1+Allowances)$$

• Allowances: Fatigue, personal needs, delays

🔹 5. Solved Examples (PYQ Style)

1. Calculate standard time for a repetitive assembly task

2. Identify unnecessary motions and suggest improvements

3. Determine worker efficiency from observed time data

4. Use micro-motion study to optimize a machine loading operation

🔹 6. Practice Exercises

1. Draw process chart for a given task

2. Solve time study problems with given stopwatch readings

3. Calculate allowances and standard time for a manual operation

4. Compare two methods and select the most efficient

5. Analyze motions using therbligs symbols

🔹 7. Summary

• Work Study: Improves method and reduces waste

• Time-Motion Study: Measures and analyzes task time and motions

• Standard Time: Combines normal time and allowances

• Exam Tip: Focus on calculation of standard time, method improvement, and motion analysis