Critical Review of Extended Waterfall Model
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International Journal of Scientific & Engineering Research, Volume 6, Issue 11, November-2015 425 ISSN 2229-5518 Critical Review of Extended Waterfall Model Rajesh H. Kulkarni, P.Padmanabham, K.K.Baseer Abstract—Software product quality improvement is a desired attribute and a strenuous effort is required to achieve that.Usability is also a desired attribute as it helps in identifying how effectively user achieves product goals.Concrete efforts to integrate Software Engineering and Human Computer Interaction exist in the form of models by many researchers. Better user experience is an oft expressed and desired quality of the products designed nowadays.Many efforts in this regard lead to various proposals of smooth integration of SE (software engineering) processes with HCI (human computer integration) for product development. One such effort is extended waterfall process model. This paper presents a critical review of extended waterfall model. It also suggests means to bring nearer the two diverse communities of SE and HCI. Index Terms— Usability, SE, HCI, Extended Waterfall Process Model. —————————— —————————— 1 INTRODUCTION He model of waterfall process refer Figure 1 in the field of T software engineering [1] has been playing a chief role Waterfall model is classic SDLC model. This model is also from the past. This model was put forth in 1950s and later, called as a heavyweight process. The lifecycle is long say six it has turned out to be a renowned model in 1970s. Its struc- months. This classic model consists of the phases: Require- ture takes the form of a cascade involving phases and it can be ment, Design, Analyze, Code, Test,and Maintain. There are viewed that the output from one phase serves as the input to other models such as Agile and RUP. In Agile Development the subsequent phase. If a single phase is considered, there the lifecycle is very small say two weeks. Requirements are will be a group of actions that several people may carry out in freezed. A scrum call is issued for not more than fifteen a simultaneous manner. The idea behind the waterfall process minutes where what today’s tasks to be done are discussed constitutes the following. (i) A linear and sequential path may and scrum master takes the onus for that. It is also called as a exist between the consecutive phases, (ii) The standards may light weight process because of shorter span of lifecycle.In be maintained at places, where the outputs or deliverables practice none of the models are followed to the tee. Every pro- could be generated or (iii) Few techniques, which aim to ject in itself is an experience. If bracketed each project is a rep- achieve the necessary output, may be suggested. The waterfall resentative of its own unique model. The reason being Re- model imparts numerous benefits.One such benefit is that it quirements are given yesterday night and the deadline for could legibly recognize the number of related phases through deliverable is within a week. It is a chaotic scenario. Most of which a process in software development should traverse. the time is spent on negotiations between client and vendor.As per Carroll et al. “Human-computer interaction (HCI) is an These phases may own varyingIJSER arrangements along with few area of research and practice that emerged in the early 1980s, changes in the scope as well as the significance and hence, initially as a specialty area in computer science embracing there is a possibility for these phases to occur in more than one cognitive science and human factors engineering. HCI has process models. Moreover, the phases involve the following: expanded rapidly and steadily for three decades, attracting (1) drawing out the requirements for specifying how the sys- professionals from many other disciplines and incorporating tem should look like at the end, (2) examining the require- diverse concepts and approaches. To a considerable extent, ments for sorting it out into functionality group and non- HCI now aggregates a collection of semi-autonomous fields of functionality group (for instance, the features), (iii) making an research and practice in human-centered informatics.”[18, 19]. architectural design for the system as well its corresponding elements, (iv) programming and executing the system, (v) The implementation and the functioning of a system will substantiating the performance of the system and its associat- be unfeasible without an integrated software engineering ed elements and (vi) subjecting the system to work in an oper- environment, which is capable of offering stability to han- ational background [2]. dle the process as well as the product. There are three lay- ers, namely, the collaboration layer, the information layer and the operational layer. The collaboration layer relies on ———————————————— the process management techniques for assisting the com- • Rajesh H. Kulkarni is currently pursuing Phd degree program in computer bined task. The information layer is one among the three engineering inJ.N.T University, Huderabad and working in JSPM NTC layers supporting the ASP system. Yet, the traditional Pune,India. E-mail: [email protected] product management systems have their centre of attrac- • P.Padmanabham is currently Director Academics in BIETin J.N.T. Uni- versityHyderabad,India,. E-mail: [email protected] tion towards the source codes or else on excellently orga- • K.K. Baseer is Phd Scholar in JNIAS-JNTUA, Anantapuramu, India, nized design details like, the transition diagrams and the India data flow diagrams. The operation layer acts as the ASP E-mail: [email protected] system’s infrastructure. IJSER © 2015 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 6, Issue 11, November-2015 426 ISSN 2229-5518 2 BACKGROUND that it still defers integration of code and testing until it is very late and when problems are harder to resolve, and hence is poor at managing risks (Kroll, et al., 2003 pp. 6, 50). The domain of software development has undergone a • SE is relatively immature in the requirements area (Suitcliffe, tremendous progress in the past forty years of research. In 2005). 1970, Winston Royce’s has granted a popular publication on • Language for communication is an issue. Improved communi- the present day waterfall scheme [3].It is this approach that cation is possible through prototypes, sketches, mock-ups, has brought about the transformation in the area of software simulations, and scenarios er (Gulliksen, et al., 2003). • development, in which the software development is imagined Communication techniques are basic. The oft-used phrase “re- quirements gathering” conjures an image in the mind’s eye to be extremely complicated and user-specific that a number that requirements are like flowers fallen overnight under a pa- of shortcomings may arise with improper arrangement.The rijatak tree, and one needs to only gather them for the morning waterfall process model serves as the conventional and typical pooja . means for developing the software.In the Waterfall process • Instead of asking users what they want and putting it into the model, the significant phases taking part are Communication, design blindly, it is much better to directly watch what users Planning, Modeling, Construction and Deployment.Further, do, identify design problems and opportunities and then design this model comprises of iterations in the form of system de- a system that solves the problems and realises the opportuni- velopment life cycle (SDLC) phases.The software developers ties. are rendered with plenty of benefits from the waterfall mod- • Conscious design decisions can be taken during communica- el.The first benefit is that the staged development cycle impos- tion phase following HCI design process. • es control because a phase will definitely have a beginning SE literature does not acknowledge that that requirements specifications already specify HCI design decisions. and ending, which allows the vendor as well as the clients to • HCI aspects are considered superficial and SE literature does fix goals to determine the advancements in a decisive way.The not mention or demonstrate the importance of considering al- time spent and the effort applied gets degraded because the ternative HCI designs. requirements and design are demanded prior to the execution • There are major gaps of communication between the HCI and of a single line of code, thus deviation from the schedule is SE fields: the architectures, processes, methods, and vocabu- prohibited.Acquiring the requirements and design at the ini- lary being used in each community are often foreign to the tial stage grants several benefits. One such is the enrichment other community.” (IFIP WG 2.7/13.4 on User Interface Engi- gained in the quality. In addition, the flaws that are likely to neering, 2004).. There is a need to have shared processes, occur can be disclosed and rectified in the design phase itself. common techniques, nomenclature, checkpoints, and measures Hence, performing flaw detection and correction in the testing for success (Jerome, et al., 2005). • phase, where the entire number of elements have undergone The HCI practitioners must have SE process support before they can deliver good quality usable software. integration and locating certain errors can be difficult, are • There is a deep- rooted myth that usability is not a central topic eliminated. The two phases in the beginning result in a formal of SE. specification and thus, the function of waterfall model is to • SE and HCI practitioners rarely collaborate and speak different assist in conveying the knowledge to the team members dis- language. tributed in various places. TheIJSER application of waterfall process • is feasible, if and only if the complete requirements exist for re-engineering the presently available SW. The commercial Critic of Waterfall model derived from [11]: projects cannot use this model practically due to the presence of iterations among the phases. Moreover, the price and dura- • Time and cost estimation is extremely difficult tion spent for system advancement and implementation is also • Upfront requirement capture and design is not realistic and large.