Software requirements (lecture 5)

1.

Software architecture
2024-2025
Gulnur Smagulova,
Major: Software Engineering
Zhuldyz Basheyeva,
Term: 2 , third year
Olzhas Aitmukhambetov
Credits: 5

2.

Software Requirements
Lecture 3

3.

Agenda
1. Fundamentals (Stakeholder Requirements)
2. Product and Process
3. Requirements
4. Specifications

4.

Fundamentals:
Stakeholder
Requirements
Stakeholder requirements serve as the
foundation for software development by
capturing the expectations and needs of
everyone involved.

5.

Key Concepts:
- Stakeholders: Individuals or groups impacted by or involved in the
system, including clients, developers, users, and managers.
- Purpose: To ensure clarity and agreement on the desired outcomes
before development begins.
- Techniques: Methods such as interviews, surveys, and observation are
used to extract stakeholder needs.
Benefits:
- Aligning the development process with business goals.
- Minimizing misunderstandings between developers and clients.

6.

Product and
Process
Requirements
Software requirements are classified into two major
types:
1.Product Requirements
2.Process Requirements

7.

Product Requirements
Define what the system should do.
- Functional requirements specify specific behaviors or functions.
- Non-functional requirements focus on system qualities like
performance, scalability, and usability.
Process Requirements
Relate to the methods and tools used during development.
- Define development constraints like timelines, technologies, or
standards.
Comparison:
- Product requirements affect the delivered system.
- Process requirements guide how the system is built.

8.

The Nature of Requirements:
Requirements
- Explicit vs. Implicit: Explicit requirements are
documented clearly, while implicit requirements may
stem from stakeholder assumptions.
- Prioritization: Assigning importance levels to
requirements using methods such as MoSCoW (Must
have, Should have, Could have, Won't have).

9.

Common Pitfalls:
- Ambiguity in documentation.
- Changes in scope mid-project.
Examples of Requirements Documentation:
- Use case diagrams (capturing functionality).
- Text-based requirement lists with unique IDs for traceability.

10.

Specifications
Purpose: Transform raw requirements into clear,
actionable documentation for developers.

11.

Key Elements:
- Requirement Specifications: Detailing each requirement with
examples, constraints, and intended functionality.
- System Models: Often using UML diagrams to visualize
system interactions (refer to component diagrams on textbook
pageY).
- Validation and Verification: Ensuring each specification aligns
with stakeholder needs and technical feasibility.

12.

Formats of Specifications:
- Textual format (tables and detailed descriptions).
-
Visual representation (e.g., sequence diagrams).
Example:
A sequence diagram illustrating user login functionality.
Stakeholders can validate this as an accurate interpretation of
their needs.

13.

- Stakeholder requirements drive the success
of software projects by aligning goals.
Conclusion
- Distinct classification between product and
process ensures holistic coverage of
constraints and capabilities.
- Well-documented
requirements
and
specifications
pave
the
way
for
maintainable, scalable, and robust systems.