Operations management: labour (labor) standards can be established using which sources or methods?

Introduction / Context:
Labour standards specify the normal time or effort required to perform a task. They are essential for capacity planning, costing, incentive systems, and scheduling. Understanding where these standards come from helps ensure that targets are both achievable and fair.

Given Data / Assumptions:

• Industrial engineering (IE) techniques such as time and motion studies are available.
• Historical performance data from the shop floor is also available.
• We seek the valid sources for setting standards.

Concept / Approach:
Two common approaches exist. Analytical methods (e.g., time and motion studies, predetermined motion-time systems) directly measure or model the work to derive a standard time. Empirical methods analyze historical data—adjusting for outliers, learning effects, and abnormal conditions—to infer a realistic standard. Many organizations triangulate both methods to improve reliability.

Step-by-Step Solution:

Verification / Alternative check:
Operations texts describe setting standards through engineered standards (stopwatch, PMTS) and through analysis of historical records corrected for allowances and performance ratings.

Why Other Options Are Wrong:

• Only time and motion: Ignores valid empirical alternatives.
• Only historical data: Ignores engineered standards that may better reflect best practice methods.
• Neither/None: Incorrect because both are recognized.

Common Pitfalls:
Using raw historical data without cleaning; setting standards from time studies but ignoring allowances (fatigue, delays) or method variation.

Final Answer:
both (a) and (b)