Comparison of Waterfall Model and Agile Methods

The waterfall model and agile methods are approaches that have emerged for the same purpose. In both approaches, planning plays an important role. While a long-term and detailed planning covering the whole process is made in the waterfall model, short-term and more detailed planning is made rather than long-term planning in order to respond to changing conditions in agile methods. The whole process is divided into release plans, release plans are divided into iteration plans, and iteration plans are divided into daily plans. Thus, more detailed targets can be set. In both approaches, detailed examinations are given importance in the process. In the waterfall model, these examinations are made through detailed controls and documentation during the transition between phases, while in agile methods, a detailed examination is provided by the working products produced as a result of iterations and the presence of the customer in the whole process. The activities carried out in both methodologies are common. The execution forms of these activities are different. In the waterfall model, these activities appear as phases applied to every requirement and are sub-components of the main process. In agile methods, they appear as activities in which each iteration is implemented, and the sub-component of the main process is the activities that make up the iterations. The basic process flows of the methodologies are shown in Figure 2 and Figure 3.

Figure 2. Waterfall Model Process Flow

Figure 3. Agile Methods Process Flow

In the waterfall model, the package of requirements progresses through phases in the project process, while in agile methods, the package consisting of phases proceeds through iterations. There is always a backwards look in the waterfall model, as the delivery is made according to the requirements and priorities defined at the beginning of the project. In agile methods, on the other hand, there is a constant forward-looking view due to the delivery according to evolving needs and priorities. While the waterfall model offers an engineering approach because it is based on structural processes, creativity is at the forefront in agile methods because it is based on people and communication.

In this article, we presented the comparison of the waterfall model and the agile method in a general framework. In order to examine more detailed comparisons; in the light of success factors of CHAOS reports, literature researches and personal experiences in software projects, comparisons and evaluations on the subjects that are considered to have an impact on project success will be presented in our upcoming articles.

References

• Gencer, C., & Kayacan, A. (2017, July 3). Yazılım Proje Yönetimi: Şelale Modeli ve Çevik Yöntemlerin Karşılaştırılması. DergiPark. Retrieved from https://dergipark.org.tr/tr/download/article-file/328845
• Standish Group International, CHAOS Report, A.B.D, 2015.
• M.S.Palmquist, M.A.Lapham, S.Miller, T.Chick, I.Ozkaya, Parallel Worlds: Agile and Waterfall Differences And Similarities, Software Engineering Institute, Carneige Mellon University, A.B.D, 2013.
• J.Fair, “Agile versus Waterfall:approach is right for my ERP Project?”, PMI® Global Congress 2012 EMEA , Marsilya, Fransa,2012.
• H.Wells, D.Dalcher, H.Smyth, “The adoption of agile management practices in a traditional Project environment: An IT/IS CaseStudy ”, 48th Hawaii International Conference on System Sciences, Hawaii, A.B.D., 4446-4453, 2015.