Development Time Calculation in cocomo model: basic cocomo model cocomo model example

Development Time Calculation in cocomo model: basic cocomo model cocomo model example

COCOMO Model – Development Time Calculation

The COCOMO (Constructive Cost Model) is a software estimation model used to calculate development effort, time, and cost based on project size (measured in KLOC – Thousand Lines of Code).

 1. Types of COCOMO Models

COCOMO has three models based on project complexity:

Basic COCOMO Model → Quick estimation (less accuracy)
Intermediate COCOMO Model → Includes cost drivers
Detailed COCOMO Model → Most accurate with multiple factors

We will focus on the Basic COCOMO Model here!

2. Basic COCOMO Model Formula

The effort (E) in person-months (PM) and development time (T in months) is calculated as:

Effort Equation:

E=a×(KLOC)bE = a \times (KLOC)^bE=a×(KLOC)b

Development Time Equation:

T=c×(E)dT = c \times (E)^dT=c×(E)d

where a, b, c, d are constants that depend on the project type.

3. COCOMO Model Categories & Constants

 4. Example Calculation (Basic COCOMO Model)

Example:

A software project is estimated to have 50 KLOC (50,000 lines of code) and is categorized as a Semi-Detached project. Calculate the Effort (E) and Development Time (T).

Solution:

From the table, for Semi-Detached Projects:

• $a=3.0$, $b=1.12$
• $c=2.5$, $d=0.35$

Step 1: Calculate Effort (E)

E=3.0×(50)1.12E = 3.0 \times (50)^{1.12}E=3.0×(50)1.12 $$E=3.0\times 64.36$$ $$E=193.08\text{ Person-Months}$$

Step 2: Calculate Development Time (T)

T=2.5×(193.08)0.35T = 2.5 \times (193.08)^{0.35}T=2.5×(193.08)0.35 $$T=2.5\times 7.24$$ $$T=18.1\text{ Months}$$

Final Answer:

• Effort = 193.08 Person-Months
• Development Time = 18.1 Months

 5. Key Takeaways

Basic COCOMO Model is a simple way to estimate effort and time.
Larger projects require more time, effort, and resources due to complexity.
More advanced versions (Intermediate, Detailed COCOMO) consider multiple cost drivers for better accuracy.

 Do you want more examples or explanations on COCOMO variations? Let me know!

Development Time Calculation in cocomo model: basic cocomo model cocomo model example

COCOMO Models

The COCOMO model (Constructive Cost Model) is a widely used algorithmic software cost estimation model developed by Barry Boehm in the early 1980s. The Basic COCOMO model estimates the effort (person-months) and development time (months) required to build a software project based on the size of the software, measured in KLOC (thousands of lines of code).

Basic COCOMO Model Formula

1. Effort (E) in Person-Months:

E=a⋅(KLOC)bE = a \cdot (KLOC)^bE=a⋅(KLOC)b

2. Development Time (D) in Months:

D=c⋅(E)dD = c \cdot (E)^dD=c⋅(E)d

The values of a, b, c, and d vary depending on the type of software project:

Project Type Definitions:

• Organic: Small, simple software projects with small teams and good experience (e.g., payroll systems).

• Semi-Detached: Intermediate complexity projects with mixed experience.

• Embedded: Complex systems with tight hardware/software constraints (e.g., real-time systems).

Example Calculation (Basic COCOMO)

Let’s say you’re estimating the development time for an Organic software project of 32 KLOC.

Step 1: Calculate Effort

Using Organic model constants: a = 2.4, b = 1.05

E=2.4⋅(32)1.05≈2.4⋅35.44≈85.06 person-monthsE = 2.4 \cdot (32)^{1.05} \approx 2.4 \cdot 35.44 \approx 85.06 \text{ person-months}E=2.4⋅(32)1.05≈2.4⋅35.44≈85.06 person-months

Step 2: Calculate Development Time

Using Organic model constants: c = 2.5, d = 0.38

D=2.5⋅(85.06)0.38≈2.5⋅5.89≈14.72 monthsD = 2.5 \cdot (85.06)^{0.38} \approx 2.5 \cdot 5.89 \approx 14.72 \text{ months}D=2.5⋅(85.06)0.38≈2.5⋅5.89≈14.72 months

Summary

For a 32 KLOC Organic project:

• Effort: ~85 person-months

• Development Time: ~15 months

Let me know if you’d like help with Intermediate or Detailed COCOMO models too!

Development Time Calculation in cocomo model: basic cocomo model cocomo model example

Software Engineering