● Basic Concepts Software Quality Factors软件质量要素： Correctness正确性：软件产品准确执行软件规格说明 中所规定的能力。 。 Robustness健壮性：在异常条件下软件仍能运行的能 力。 。 Reliability可靠性：软件在给定的时间内和规定的环境 条件下，按规格说明的规定成功地运行的概率。可靠 性理解为正确性和健壮性之和
Basic Concepts Software Quality Factors 软件质量要素： • Correctness 正确性：软件产品准确执行软件规格说明 中所规定的能力。 • Robustness 健壮性：在异常条件下软件仍能运行的能 力。 • Reliability 可靠性：软件在给定的时间内和规定的环境 条件下，按规格说明的规定成功地运行的概率。可靠 性理解为正确性和健壮性之和
● System Engineering What is it? Before software can be engineered,the "system"in which it resides must be understood.To accomplish this, the overall objective of the system must be determined; 。 the role of hardware,software,people,database,procedures,and other system elements must be identified; 。 and operational requirements must be elicited,analyzed,specified. modeled,validated,and managed. These activities are the foundation of system engineering ●
System Engineering What is it? Before software can be engineered, the “system” in which it resides must be understood. To accomplish this, • the overall objective of the system must be determined; • the role of hardware, software, people, database, procedures, and other system elements must be identified; • and operational requirements must be elicited, analyzed, specified, modeled, validated, and managed. These activities are the foundation of system engineering
● System Engineering Who does it? A system engineer works to understand system requirements by working with the customer,future users,and other stakeholders. ●
System Engineering Who does it? • A system engineer works to understand system requirements by working with the customer, future users, and other stakeholders
● System Engineering Why is it important? 。 There is an old saying:"You cannot see the forest for the trees."In this context,the "forest"is the system,and the trees are the technology elements (include software)that are required to realize the system.If you rush to build technology elements before you understand the system, you will undoubtedly make mistakes that will disappoint your customer.Before you worry about the trees, understand the forest. ● ● ●
System Engineering Why is it important? • There is an old saying：“You cannot see the forest for the trees.”In this context, the “forest”is the system, and the trees are the technology elements (include software) that are required to realize the system. If you rush to build technology elements before you understand the system, you will undoubtedly make mistakes that will disappoint your customer. Before you worry about the trees, understand the forest
● System Engineering What are the steps? 。 Objectives and more detailed operational requirements are identified by eliciting information from the customer. Requirements are analyzed to assess their clarity, completeness,and consistency. 。 A specification,often incorporating a system model,is created and then validated by both practitioners and customers. System requirements are managed to ensure that changes are properly controlled ●
System Engineering What are the steps? • Objectives and more detailed operational requirements are identified by eliciting information from the customer. • Requirements are analyzed to assess their clarity, completeness, and consistency. • A specification, often incorporating a system model, is created and then validated by both practitioners and customers. • System requirements are managed to ensure that changes are properly controlled