Time Study and Standard Time

Time study establishes realistic standard time by combining observed cycles, rating, and allowances.

Key formulas & points

Skim these first — then read the full notes below.

  • Multiple cycles averaged; discard abnormal
  • Contingency allowance for minor delays
  • Standard data from MTM-1, MTM-2 databases

Topic details

Introduction

This topic links work-study fundamentals to production control. Chase and Groover both treat standard time as a planning baseline for staffing, scheduling, and cost estimation.

Key relations & formulas

standardtime=NT×standard time = NT \times
(1 + A/100)

Formulas (Indian textbook notation)

  • cycletime=productiontimeunitsproducedcycle time = production \frac{time}{units} produced

Formulas (Indian textbook notation)

  • takttime=availabletimecustomerdemandtakt time = available \frac{time}{customer} demand

Notation and sign conventions

Relation 1 —
standardtime=NT×standard time = NT \times
standardtime=NT×standard time = NT \times
(1 + A/100)
Write this relation with symbols exactly as in Industrial Engineering & Management — O.P. Khanna before substituting numbers. Examiners award partial marks for a correct setup even when arithmetic slips.
Relation 2 —
cycletime=productiontimeunitsproducedcycle time = production \frac{time}{units} produced

Formulas (Indian textbook notation)

  • cycletime=productiontimeunitsproducedcycle time = production \frac{time}{units} produced
Write this relation with symbols exactly as in Industrial Engineering & Management — O.P. Khanna before substituting numbers. Examiners award partial marks for a correct setup even when arithmetic slips.
Relation 3 —
takttime=availabletimecustomerdemandtakt time = available \frac{time}{customer} demand

Formulas (Indian textbook notation)

  • takttime=availabletimecustomerdemandtakt time = available \frac{time}{customer} demand
Write this relation with symbols exactly as in Industrial Engineering & Management — O.P. Khanna before substituting numbers. Examiners award partial marks for a correct setup even when arithmetic slips.

Concept in depth

Cycle time reflects actual pace, takt time reflects market requirement, and standard time reflects expected sustainable pace including allowances. In B.Tech numericals, students should clearly present sequence: observations -> average -> rating correction -> allowances. Mahajan-based solving format with unit checks gives clean scoring.

Assumptions and validity limits

State assumptions explicitly before using any relation for time study and standard time — steady state, uniform properties, linear elastic material, ideal gas, incompressible flow, etc., as applicable.
Wrong assumptions invalidate the entire solution even when the formula is correct. In Work Study viva and GATE descriptive questions, listing valid assumptions often earns separate marks.

Step-by-step problem approach

1. Read the question and list given data with SI units (common in Work Study papers).
2. Draw a neat labelled diagram where applicable — examiners in Indian universities award diagram marks even when arithmetic slips.
3. Identify which relation from this topic applies to time study and standard time.
4. Use equation 1:
standardtime=NT×standard time = NT \times
.
5. Use equation 2:
cycletime=productiontimeunitsproducedcycle time = production \frac{time}{units} produced
.
6. Substitute values, compute, and verify units and sign (direction).
7. State conclusion in one line — e.g. safe/unsafe, stable/unstable, feasible/infeasible.

Applications & exam relevance

Time Study and Standard Time appears in line balancing and productivity. In Indian industrial curricula this topic is tested because it connects theory to method study and time standards.
GATE and semester exams often combine time study and standard time with earlier units — revise prerequisites before attempting mixed problems.
Industry interview panels sometimes ask: "Where did you use time study and standard time?" — answer with a lab, mini-project, or plant visit example if possible.

Common mistakes in exams

Students often confuse takt time with cycle time. Another repeated issue is using allowance percentage as A instead of A/100 in formula substitution.

Quick revision checklist

Before attempting time study and standard time problems, confirm you can:
1. Multiple cycles averaged; discard abnormal
2. Contingency allowance for minor delays
3. Standard data from MTM-1, MTM-2 databases
Revise the solved examples in Industrial Engineering & Management — O.P. Khanna and one previous-year GATE or university paper for this unit.

Worked examples

Try the problem first — open the solution when you are ready to check.

Takt vs cycle gap

Problem

Available time is 420 min/day and customer demand is 210 units/day. Actual cycle time is 2.4 min/unit. Comment on pace.

Solution

Takt time = 420/210 = 2.0 min/unit. Since actual cycle time 2.4 > takt 2.0, the line is slower than demand and will miss daily target unless improved.

Conceptual check — Time Study and Standard Time

Problem

In a Work Study semester or GATE paper you are asked: "State the main assumption, the governing relation, and one practical consequence of time study and standard time." What should a complete answer include?

Exams & GATE

Calculate standard time with rating and allowance — typical IE exam.

📖 Standard books (India)

  • Industrial Engineering & ManagementO.P. Khanna

    Read: Syllabus unit

    Work study, PPC, and OR basics