Software Engineering with Agile Methodology (AD-403) - Unit 4 Short Notes

How unit 4 is examined

This unit covers what Agile is, its life cycle, values, principles, phases, and how it compares with Waterfall; the marks sit in Agile vs Traditional, Benefits and Challenges, and the Manifesto, Values and Phases questions.

Introduction to Agile software development methodology

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Definition. <mark>Agile is an iterative and incremental approach to software development in which self-organising cross-functional teams deliver small working increments quickly, welcome changing requirements and work closely with the customer.</mark>

Key points.

1. Software is built in short time-boxed iterations (sprints) of usually one to four weeks, and each iteration ends with working software.
2. Requirements are expected to change, so the plan is revisited every iteration instead of being frozen at the start.
3. The customer takes part throughout and gives feedback on every increment.
4. Agile prefers face-to-face communication and working software over heavy documents and rigid process.
5. Popular Agile methods are Scrum, XP, Kanban, Crystal, ASD and DSDM; all follow the Agile Manifesto (2001).

Life Cycle of Agile development

<span style="display:inline-block;padding:.16em .6em;border:1.5px solid currentColor;border-radius:999px;font-size:.68em;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.75">Not asked since 2022</span>

Definition. <mark>The Agile life cycle is a repeating loop of plan, design, build, test, release and review, run once per iteration so that each cycle adds a working increment.</mark>

Key points.

1. It begins with a short concept or vision step, where the product backlog (the list of wanted features) is created and prioritised.
2. Each iteration picks the highest-priority backlog items, designs, codes and tests them, and delivers a potentially shippable increment.
3. At the end of the iteration the team demonstrates the increment, collects customer feedback and holds a retrospective.
4. Feedback goes back into the backlog, so the next iteration starts with better information.
5. The cycle repeats until the product is complete, then the product is released and maintained.

Agile v/s Traditional software development (Waterfall model)

<span style="display:inline-block;padding:.16em .6em;border:1.5px solid currentColor;border-radius:999px;font-size:.68em;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.75">Medium weight</span>

Definition. <mark>Agile is an iterative, incremental, customer-collaborative approach that values individuals, working software and responding to change; the traditional (Waterfall) model is a linear, plan-driven approach in which requirements, design, coding, testing and maintenance follow one another in strict order.</mark>

Key points.

1. Agile follows the four Manifesto values (individuals and interactions, working software, customer collaboration, responding to change) over process, documentation, contracts and plans.
2. Waterfall completes each phase fully before the next begins, so a mistake found late is expensive to fix.
3. Agile delivers working software in frequent small releases, while Waterfall delivers only once, at the end.
4. In Agile the customer is involved throughout; in Waterfall the customer mainly appears at requirements and acceptance.
5. Agile welcomes change even late in development; Waterfall resists change after requirements are frozen.

Answer frame. Open with the definition of Agile and its four values; draw or write the phase-wise picture (Waterfall as a straight cascade, Agile as repeated small loops); then give the table in the order approach, requirements, delivery, customer, change, documentation, testing; close with suitability, that Agile fits changing requirements and Waterfall fits stable, safety-critical projects.

Pitfall: Writing only the definitions and no row-wise comparison loses most of the marks.

Asked: [7 marks] (Jun 2023, Jun 2024, Jun 2025) Define Agile. Explain how agile software development model is different from traditional development model. / How is agile methodology different from traditional methodologies? / Compare Agile development with the Waterfall model.

Agile Manifesto: Principles

<span style="display:inline-block;padding:.16em .6em;border:1.5px solid currentColor;border-radius:999px;font-size:.68em;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.75">Low weight</span>

Definition. <mark>The Agile Manifesto is a short statement written in 2001 by seventeen software developers at Snowbird, Utah, that states four values and twelve principles for better software development.</mark>

Key points.

1. The four values are individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and responding to change over following a plan.
2. Twelve principles include satisfying the customer through early and continuous delivery, welcoming changing requirements, delivering working software frequently, daily cooperation between business people and developers, and building projects around motivated individuals.
3. Further principles stress face-to-face conversation, working software as the main measure of progress, sustainable pace, technical excellence, simplicity, self-organising teams and regular reflection on how to improve.
4. Benefits are flexibility, higher customer satisfaction, better quality and faster delivery; unlike traditional models, it does not freeze the plan.

Asked: [7 marks] (Jun 2025) What is the Agile Manifesto? Discuss its principles and benefits.

Benefits and Challenges of Agile

<span style="display:inline-block;padding:.16em .6em;border:1.5px solid currentColor;border-radius:999px;font-size:.68em;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.75">Medium weight</span>

Definition. <mark>Benefits are the advantages that iterative, customer-focused delivery brings; challenges (obstacles) are the organisational and technical difficulties that make adopting Agile hard.</mark>

Key points.

1. Benefits: the customer sees working software early and often, so satisfaction and collaboration improve.
2. Benefits: changing requirements are accepted at low cost, which gives flexibility, and continuous testing gives better quality with early defect detection.
3. Benefits: risk is reduced because problems appear in a small iteration, and time to market is faster.
4. Challenge, culture and resistance to change: teams and managers used to command-and-control resist self-organisation and new roles.
5. Challenge, customer availability: Agile needs constant customer feedback, which is hard when the customer is busy or absent.
6. Challenge, distributed teams and scaling: face-to-face communication is difficult across locations, and Agile is hard to scale to large teams or big projects.
7. Challenge, documentation, contracts and management: light documentation hurts maintenance and new members, fixed-price contracts clash with changing scope, and estimating cost and schedule is difficult.
8. Challenge, discipline: weak planning can cause scope creep and needs an experienced, disciplined team.

Answer frame. Open with the definition of Agile; write benefits as points 1-3, then challenges as points 4-8 (culture, customer, distributed and scaling, documentation and contracts, discipline); close that Agile suits small to medium projects with changing requirements and an involved customer.

Asked: [7 marks] (Jun 2023, Jun 2024) What are the obstacles to the Agile process? / Discuss in detail about the Benefits and Challenges of Agile.

Agile Values

<span style="display:inline-block;padding:.16em .6em;border:1.5px solid currentColor;border-radius:999px;font-size:.68em;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.75">Low weight</span>

Definition. <mark>Agile values are the four preferences of the Manifesto that shape the agile mindset: individuals and interactions over processes and tools; working software over comprehensive documentation; customer collaboration over contract negotiation; responding to change over following a plan.</mark>

Key points.

1. The mindset is a way of thinking, and values give it direction because they decide what the team chooses when there is a conflict.
2. Individuals and interactions build trust and teamwork, which produce better solutions than tools alone.
3. Working software is the true measure of progress, so the team focuses on delivering value, not paperwork.
4. Customer collaboration keeps the product aligned with real needs, and responding to change makes change an opportunity, not a threat.
5. The right side of each value still matters, but the left side is valued more; so values drive daily behaviour.

Asked: [7 marks] (Jun 2023) Explain why do you think agile values are most needed for the agile mindset?

Agile Model

<span style="display:inline-block;padding:.16em .6em;border:1.5px solid currentColor;border-radius:999px;font-size:.68em;font-weight:700;letter-spacing:.06em;text-transform:uppercase;opacity:.75">Not asked since 2022</span>

Definition. <mark>The Agile model is a software process model that combines iterative and incremental development, where the product is built in small increments through repeated short cycles with continuous customer feedback.</mark>

Key points.

1. The work is split into small increments, and each one is planned, developed, tested and released within a short iteration.
2. Every increment is a working piece of the final product, so the customer can use and review it early.
3. Requirements are collected as user stories and kept in a prioritised backlog that can change at any time.
4. Testing and integration happen continuously, and daily stand-up meetings keep the team synchronised.

Phases of Agile Model

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Definition. <mark>The Agile model has four phases in sequence: requirement gathering and planning, design, development (build and test), and deployment with review; the four repeat for every iteration.</mark>

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Key points.

1. Requirements and planning: the team and customer choose the backlog items for the iteration and estimate the effort.
2. Design: a simple design is prepared for the selected items, only as much as needed.
3. Development: the team codes and tests the items, integrating often.
4. Deployment and review: the increment is released or demonstrated, feedback is taken, and the cycle repeats.

Asked: [7 marks] (Jun 2023) What are the 4 unique phases in Agile model in sequence?

Last-minute revision

• Agile is iterative and incremental, with working software delivered in short iterations of 1-4 weeks.
• The Manifesto was written in 2001 by 17 developers; it has 4 values and 12 principles.
• Four values: individuals over processes, working software over documentation, customer collaboration over contracts, responding to change over plans.
• Waterfall is linear and freezes requirements; Agile welcomes change and delivers frequently.
• Benefits: flexibility, customer satisfaction, quality, early risk detection, faster delivery.
• Challenges: culture, customer availability, distributed teams, scaling, documentation, contracts, discipline.
• Four phases: requirements and planning, design, development, deployment and review.
• The product backlog holds prioritised user stories; the retrospective closes each iteration.

Memory hooks

• ICCR for the values: Individuals, Customer, Change, working software (Running).
• RDDD for the phases: Requirements, Design, Development, Deployment.
• Waterfall is a waterfall (one way down); Agile is a loop of small waterfalls.
• CDDSD for challenges: Culture, Distributed, Documentation, Scaling, Discipline.

Coverage checklist

• Introduction to Agile software development methodology: definition, iterations, customer feedback, methods.
• Life Cycle of Agile development: backlog, iteration loop, review, retrospective.
• Agile v/s Traditional software development(Waterfall model): definition, 8-row table (Jun 2023, Jun 2024, Jun 2025).
• Agile Manifesto: Principles: values, principles, benefits (Jun 2025).
• Benefits and Challenges of Agile: benefits and obstacles (Jun 2023, Jun 2024).
• Agile Values: four values and mindset (Jun 2023).
• Agile Model: increments, user stories, continuous testing.
• Phases of Agile Model: four phases in sequence (Jun 2023).