Software Engineering Chapter 7 Requirements Engineering Processes KuYaw

Software Engineering Chapter 7 Requirements Engineering Processes Ku-Yaw Chang canseco@mail. dyu. edu. tw Assistant Professor Department of Computer Science and Information Engineering Da-Yeh University Ku-Yaw Chang Software Requirements

Objectives To describe the principal requirements engineering activities and their relationships To introduce techniques for requirements elicitation and analysis To describe requirements validation and the role of requirements reviews To discuss the role of requirements management in support of other requirements engineering processes Ku-Yaw Chang Software Requirements 2

Preamble The goal of requirements engineering process n To create and maintain a system requirement document Four high-level sub-processes n Feasibility study Assess whether the system is useful to the business n Elicitation and analysis Discover requirements n Specification Convert requirements into some standard form n Validation Check the requirements actually define the system that the customer want Ku-Yaw Chang Software Requirements 3

Requirements Engineering Process Ku-Yaw Chang Software Requirements 4

Spiral Model of Requirements Engineering Processes Ku-Yaw Chang Software Requirements 5

Contents 7. 1 Feasibility studies 7. 2 Requirements elicitation and analysis 7. 3 Requirements validation 7. 4 Requirements management Ku-Yaw Chang Software Requirements 6

Contents 7. 1 Feasibility studies 7. 2 Requirements elicitation and analysis 7. 3 Requirements validation 7. 4 Requirements management Ku-Yaw Chang Software Requirements 7

Process Activities Requirements discovery n Interacting with stakeholders to discover their requirements. Domain requirements are also discovered at this stage. Requirements classification and organization n Groups related requirements and organizes them into coherent clusters. Requirements prioritization and negotiation n Prioritizing requirements and resolving requirements conflicts. Requirements documentation n Requirements are documented and input into the next round of the spiral. Ku-Yaw Chang Software Requirements 8

Requirements Elicitation and Analysis Process Ku-Yaw Chang Software Requirements 9

7. 2. 1 Requirement Discover The process of n n Gathering information about the proposed and existing systems Distilling the user and system requirements from this information Techniques n n Interviewing Scenarios Use-cases n Ethnography Ku-Yaw Chang Software Requirements 10

Scenarios Easier to relate to real-life examples Each scenario covers one or more possible interactions Ku-Yaw Chang Software Requirements 11

Use-cases A scenario-based technique Ku-Yaw Chang Software Requirements 12

LIBSYS use cases Ku-Yaw Chang Software Requirements 13

Contents 7. 1 Feasibility studies 7. 2 Requirements elicitation and analysis 7. 3 Requirements validation 7. 4 Requirements management Ku-Yaw Chang Software Requirements 14

Contents 7. 1 Feasibility studies 7. 2 Requirements elicitation and analysis 7. 3 Requirements validation 7. 4 Requirements management Ku-Yaw Chang Software Requirements 15