What are common examiner traps in COCOMO Model?

Expressing development time D directly as a power function of KLOC rather than as a function of Effort E. Swapping the dependent and independent variables between effort and time (e.g., calculating E as a function of D). Confusing the multiplicative constants (ab, cb) with the exponential scaling factors (bb, db).

COCOMO Model

1 Qs · 2015 · 1 marks · 0.1 marks/paperStandard yield

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In GATE CS, the COCOMO (Constructive Cost Model) topic tests foundational knowledge of empirical software cost estimation models. The exam focuses on the mathematical formulation c… Guide

Type

GATE CSE 2015 Set 2Q12MCQ1 markEasyConsider the basic COCOMO model where $E$ is the effort applied in person-months, $D$ is the development time in chronological months, $KLOC$ is the estimated number of delivered lines of code (in thousands) and $a_b, b_b, c_b, d_b$ have their usual meanings. The basic COCOMO equations are of the form

Topic guide

What does GATE test in COCOMO Model?

In GATE CS, the COCOMO (Constructive Cost Model) topic tests foundational knowledge of empirical software cost estimation models. The exam focuses on the mathematical formulation connecting software size (KLOC), development effort (person-months), and nominal development schedule/time (months). Questions evaluate whether candidates understand the power-law dependencies and parameter roles in the Basic COCOMO model.

Core concepts

Basic COCOMO model equations
Effort estimation in Person-Months (E)
Development time / schedule estimation in Chronological Months (D)
Source code sizing in KLOC (Thousands of Lines of Code)
COCOMO empirical constants and power-law parameters (ab, bb, cb, db)

Recurring question patterns

Standard Equation Identification for Basic COCOMO
rare · MCQ · 1 marks · 2015
Identifying the correct algebraic forms for Effort ( $E$ ) as a power function of size (KLOC) and Development Time ( $D$ ) as a power function of Effort ( $E$ ).

Formulas GATE uses

Basic COCOMO Effort Equation

E = a_b (\text{KLOC})^{b_b}

Used to estimate total effort in person-months given the software size in thousands of lines of code (KLOC).

Basic COCOMO Development Time Equation

D = c_b (E)^{d_b}

Used to estimate the chronological project duration (schedule) in months using the estimated effort $E$ .

Examiner traps in COCOMO Model

Expressing development time D directly as a power function of KLOC rather than as a function of Effort E.
Swapping the dependent and independent variables between effort and time (e.g., calculating E as a function of D).
Confusing the multiplicative constants (ab, cb) with the exponential scaling factors (bb, db).

How questions are asked

Identify standard equation formulation
Parametric relationship identification

Paper trends

Appeared as a direct, recall-based 1-mark MCQ testing standard equation forms under the Basic COCOMO specification.
2015

Difficulty notes

Easy questions test direct recall of the functional forms of the Basic COCOMO formulas ( $E$ from KLOC, $D$ from $E$ ). Medium questions require numerical computation of effort, duration, or average staff size ( $SS = E / D$ ) given empirical constants for specific project modes (Organic, Semidetached, Embedded).