Proceedings of the 28th Annual International Computer Software and Applications Conference (2004) Ming Huo, June Verner, Liming Zhu, Muhammad Ali Babar Software Quality and Agile Methods 學生：詹博丞、林帝丞、徐子濠

Outline Introduction Waterfall model vs. Agile Methods Quality assurance techniques Agile methods quality techniques Conclusions 2

Introduction Agile software development has become a controversial software engineering topic. Agile methods have gained tremendous acceptance in the commercial arena since late 90s. In this paper, we compare the waterfall model with agile processes to show how agile methods achieve software quality. 3

Outline Introduction Waterfall model vs. Agile Methods Quality assurance techniques Agile methods quality techniques Conclusions 4

Waterfall model Waterfall model has been widely used in both large and small software projects. The waterfall model divides the software development lifecycle into five stages. Requirements analysis and definition System and software design Implementation and unit testing Integration and system testing Operation and maintenance 5

Waterfall model (cont.) Any stage should not start until the previous stage has finished. Drawbacks Inflexibility Highly ceremonious processes 6

Agile Methods Agile methods deal with unstable and volatile requirements by using a number of techniques : Simple planning Short iteration Earlier release Frequent customer feedback 7

One Agile release vs. Waterfall Lifecycle 8

Outline Introduction Waterfall model vs. Agile Methods Quality assurance techniques Agile methods quality techniques Conclusions 9

Quality assurance techniques Concerned with the quality of software produced with the waterfall model and an agile approach We focus on two general quality-focused processes Software Quality Assurance (SQA) Verification and Validation(V&V) 10

Quality assurance techniques Software Quality Assurance (SQA) SQA governs the procedures meant to build the desired quality into the products Verification and Validation(V&V) V&V is aimed more directly at product quality including intermediate products 11

Quality assurance techniques SQA and V&V are normally used to support the waterfall model to provide a complete process mode QA techniques can be categorized into two types Static Static techniques involve examination of documentation by individuals or groups E.g requirements specification, technical reviews of the code Dynamic Testing Simulation 12

Quality assurance techniques The waterfall model uses both static and dynamic techniques. Agile methods mostly use dynamic techniques. 13

Outline Introduction Waterfall model vs. Agile Methods Quality assurance techniques Agile methods quality techniques Conclusions 14

Waterfall model include: Requirements definition System and software design Implementation and unit testing Integration and system testing Operation and maintenance 15 Agile methods quality techniques

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Agile methods quality techniques two major differences between waterfall model and agile method: 1. agile methods move some QA responsibilities and work to the developers. 2. output is sent frequently to quality assurance practices and fast feedback is provided 17

Agile methods quality techniques 18 main sequence Quality Assurance

Agile methods quality techniques (cont.) Features: System metaphor On-site customer Pair programming Refactoring Continuous integration Acceptance testing Customer feedback 19

Agile methods quality techniques (cont.) Differences between the SQA: Fewer static quality assurance techniques. Frequency of these activities is much greater. Quality activities occur much earlier 20

Agile methods quality techniques (cont.) The QA techniques for agile methods: Applying dynamic QA techniques as early as possible. Moving more QA responsibility on to the developer. Early product validation. 21

Agile methods quality techniques (cont.) 22

Outline Introduction Waterfall model vs. Agile Methods Quality assurance techniques Agile methods quality techniques Conclusions 23

Conclusions 24 Agile methods do have practices that have QA abilities, some of them are inside the development phase and some others can be separated out as supporting practices. The frequency with which these agile QA practices occur is higher than in a waterfall development Agile QA practices are available invery early process stages due to the agile process characteristics