lesson_04.md 2.3 KB
SE2 - lesson 04
Elisabeta di Nitto
15 October 2015
Requirement analisys pt.II
The boundary between the world and the machine may vary
The purpose of a RE activity is:
- Identify the goals of the project
- Explore alternative ways of satisfying the goals
- Evaluate strenght and risks of each alternative, to select the most appropriate
Requirement Analisys and Specification Document - RASD
- It is used as a baseline for software evaluation
Stakeholders of the RASD
- Customers & users
- System analysts, requirements analysts
- Developers, Programmers
- Testers
- Project managers
It tipically has a multilevel structure, and it's defined by IEEE standard
- Introduction
- Purpose
- Scope: Identifies the product and the application domain
- Definitions, acronyms, abbreviations
- Reference documents
- Overview
- Overall Description
- Product perspecive: Describes all esxternal interfaces (system, user, hardware, ...)
- Produt functions
- Specific Requirements: the body of the document
section 3: Specific Requirements
3.1 External interface requirements
- 3.1.1 User interfaces
- 3.1.2 H
3.2 Functional Requirements
3.3 Performance Requirements
3.4 Design Constraints
3.5 Software System Attributes
3.6 Other Requirements
Target qualities for a RASD
- Completeness
- Pertinence
- Consistency
- Unambiguity
- Feasibility
- Comprehensibility
- Good Structuring
- Modifiability
- Traceability
Functional Requirements bad examples
The system shall validate and accept credit cards and cashier's checks. High priority.
Two requirements are expressed together.
The system shall process all mouse clicks very fast to ensure users do not have to wait
This requirement is not specific, it doesn't give a measure of "fast"
The user must have Adobe Acrobat installed
It is a constraint, not a requirement.
Types of requirements
- Functional requirements
- Nonfunctional requirements
- Constraints
While functional requirements have to be provided by the end user, Nonfunctional requirements are independend of the application domain
Nonfunctional requirements are also calles QoS requirements
Project initiation
An important step is making an Interview with the customers