Assignment no 1
Course:
Software Engineering
Registration No:
SP24-BSE-008(2-A)
Submission Date:
11 October 2024
Submitted to:
Ms. Sana Farooq
Submitted by:
Affan Ahmad
COMSATS UNIVERSITY ISLAMABAD, SAHIWAL
CAMPUS
Spiral Model:
The spiral model was developed by “Barry Boehm” in the year 1986 as a part of
SEI (Software Engineering Institute).
Definition:
The Spiral Model is a software development process (SDLC) model that combines
elements of linear and iterative models, emphasizing risk management, customer
involvement, and continuous refinement.
Explanation:
It is called meta model because it contains all the life cycle model. The main
purpose of spiral model is to reduce the risk in the project spiral model has been
introduced. One business analyst is required to reduce the risk with the help of
developer and client then we can say how much cost it will take to developed. This
model is mainly suitable for large and complex projects. It is called a spiral
because same activities are repeated for all the loops(spiral). Each spiral or loop
represent the software development process.
Key Characteristics of the Spiral Model:
1. Iterative Cycles (Spirals): Development is divided into a series of
iterative cycles or "spirals." Each cycle includes planning, risk analysis,
design, implementation, and evaluation. The project moves through multiple
spirals, where each one expands on the work done in the previous one.
2. Risk Management: A major feature of the spiral model is its focus on
risk analysis. At every iteration, risks are identified and assessed. This helps
in minimizing project failures.
3. Phases of the Spiral:
o Planning Phase: Objectives, alternatives, and constraints are
established.
o Risk Analysis Phase: Risks are analyzed, and mitigation strategies
are devised.
o Engineering Phase: Development and testing take place.
o Evaluation Phase: Stakeholders review the output to decide if the
project should continue, adjust, or terminate.
4. Flexibility and Adaptability: Since the model is iterative, it allows
changes in requirements based on stakeholder feedback, making it adaptable
to evolving project needs.
5. Progressive Refinement: With each cycle, the product is refined and
expanded upon, incorporating lessons learned from previous iterations. This
results in gradual, step-by-step refinement toward the final system.
Diagram of the Spiral Model:
Advantages:
• Effective risk management
• Used for large projects
• Flexible
• Improved customer satisfaction
Disadvantages:
• Customer software development
• Expensive
• Too much risk analysis
• Difficult to predict project timeline and cost
Real world scenario:
A real-world scenario where the Spiral Model is effectively used is in the
development of a large-scale defense or aerospace system. These types of
projects involve complex requirements, high risks, and the need for high safety and
security standards. Here’s how the Spiral Model fits into this context:
Scenario: Development of an Air Traffic Control System
The goal is to build a robust, scalable, and secure air traffic control (ATC)
system for a large national airspace. Such a system involves integration with
existing radar, communication systems, and software platforms, ensuring real-time
data processing and reliability.
How the Spiral Model Applies:
1. First Spiral: Feasibility and Risk Analysis
o Objective: In the first spiral, the project team works on understanding
the system’s high-level requirements, including safety standards, real-
time data processing, and coordination between air traffic control
centers.
o Risk Identification: Since air traffic control involves life-critical
systems, risks like system failures, security breaches, or data delays
must be evaluated.
The outcome of this phase includes a preliminary system design, and
an initial assessment of high-risk areas (e.g., data redundancy, security
vulnerabilities).
2. Second Spiral: System Design and Risk Mitigation
o Objective: Based on feedback from the first spiral, the team designs a
high-level architecture. This phase focuses on defining system
components (like real-time communication, radar integration, and
backup systems).
o Risk Analysis: The risk of data bottlenecks and delays in real-time
data processing is identified. The project team develops strategies like
redundant data channels or improving communication protocols to
mitigate these risks.
A more detailed design is produced, along with prototype components
of the system, such as radar integration modules.
3. Third Spiral: Prototype Development and Testing
o Objective: The team now focuses on building and testing key
components. The prototype might include a simulation of air traffic
control functions, allowing the system to track aircraft and process
real-time data.
o Risk Mitigation: Testing includes evaluating system performance
under stress, ensuring that the system can handle high volumes of air
traffic without delays. Security protocols are also tested to prevent
cyberattacks.
A working prototype of the air traffic control system that meets initial
requirements. Based on feedback and test results, further risks are
identified.
4. Fourth Spiral: Full System Development and Integration
o Objective: Once the prototype is validated, the full system is
developed and integrated into the national air traffic network. This
includes scaling up the system to support all control centers and
implementing redundant servers for failover.
o Risk Mitigation: Ongoing risk management ensures that new
challenges, such as system performance across different regions or
data synchronization between multiple control centers, are handled.
Outcome: The final product is ready for deployment after extensive testing.
However, the system continues to evolve with future spirals to accommodate
updates and address new risks.
Why the Spiral Model Works Here:
• Risk Management: Managing risk in a critical system like ATC is essential
because system failures could result in loss of life. The Spiral Model's focus
on identifying and mitigating risks at every stage ensures a reliable and
secure system.
• Complexity: The ATC system is extremely complex, requiring integration
with multiple subsystems and real-time operations. The iterative approach of
the Spiral Model helps in breaking down the complexity into manageable
stages.
• Changing Requirements: Over time, new regulations, technologies, or
operational needs may arise. The flexibility of the Spiral Model allows the
ATC system to evolve by incorporating new requirements and technologies
in future iterations.
In this scenario, the Spiral Model helps manage the high risk, complexity, and
evolving requirements that are characteristic of building a critical, large-scale air
traffic control system.
