Time Study and Work Measurement

Why it matters

Time Study and Work Measurement are crucial for optimizing productivity and efficiency in industrial settings. By accurately measuring the time taken for tasks, engineers can identify bottlenecks and improve processes, leading to cost savings and increased output.

Key ideas

• Time Study: A technique used to determine the time required for a qualified worker to complete a task at a defined level of performance. It involves breaking down tasks into smaller elements and timing each element.
• Work Measurement: Encompasses various techniques like time study, work sampling, and predetermined motion time systems (PMTS) to establish standard times for tasks.
• Standard Time: The time allowed for a task, including allowances for rest and delays. It is calculated as Standard Time = Normal Time + Allowances.
• Normal Time: The time taken by a worker to complete a task under normal working conditions, calculated as Normal Time = Observed Time × Performance Rating.
• Performance Rating: A factor used to adjust the observed time to reflect the worker's speed relative to a standard.
• Allowances: Additional time added to account for fatigue, delays, and other factors.

Formulas

• Normal Time = Observed Time × Performance Rating
  • Observed Time: Time recorded during the study (seconds or minutes)
  • Performance Rating: A decimal representing worker performance (no unit)
• Standard Time = Normal Time + Allowances
  • Normal Time: Time adjusted for performance (seconds or minutes)
  • Allowances: Additional time for delays and fatigue (seconds or minutes)

The rating factor is a multiplier relative to standard pace: a factor 1.1 means the observed worker was assessed as faster than standard, so normal time is longer than observed time. A fixed allowance in minutes is added directly. Percentage allowances need a declared normal-time or standard-time basis. Collect representative cycles and investigate abnormal observations rather than relying on one arbitrary timing.

Worked example

Given:

• Observed Time for a task: 30 minutes
• Performance Rating: 1.1
• Allowances: 5 minutes

1. Calculate the Normal Time.

   • Formula: Normal Time = Observed Time × Performance Rating
   • Calculation: Normal Time = 30 min × 1.1 = 33 min

2. Calculate the Standard Time.

   • Formula: Standard Time = Normal Time + Allowances
   • Calculation: Standard Time = 33 min + 5 min = 38 min

Final Answer: 38 minutes

Common mistakes

• Ignoring Allowances: Students often forget to add allowances to the normal time, leading to underestimation of the standard time.
• Incorrect Performance Rating: Misjudging the performance rating can result in inaccurate normal time calculations.
• Unit Conversion Errors: Failing to maintain consistent units throughout calculations.

For GATE ME

Questions typically involve calculating normal and standard times, understanding the impact of performance ratings, and applying work measurement techniques. Practice problems should focus on time study calculations and understanding allowances.

Quick check

1. What is the purpose of a time study?
2. How do you calculate normal time?
3. Why are allowances added to normal time?

Answers: 1. To determine the time required for a task. 2. Observed Time × Performance Rating. 3. To account for fatigue and delays.