How to Effectively Use DSDM Methodology in Development Methods - Research Paper Example

How to effectively use DSDM Methodology in conjunction with development methods like the XP Dynamic System Development Model (DSDM) is a software development methodology that focuses on user involvement and incremental process of software development. Developed in UK, DSDM focuses on the notion that no system is perfect during its first stage of development. It therefore follows nine principles which govern how software should be developed using this methodology (Highsmith). With its 9 principles, DSDM provides a rich methodology of developing information systems to cater for nearly all user requirements identified in the requirements specification. This can be further enhanced by incorporating other development methodologies like extreme programming (XP) or Unified Software Development Process during different stages of project development. The nine principles of DSDM include: i. User involvement. The focus of user involvement is based on the idea that both system users and the developers participate together during the development process sharing ideas and building the system incrementally. This ensures that the final system is accepted by both parties. ii. Empowering of project teams in decision making. In a project using DSDM, the project teams are empowered to make major decisions that dictate the direction of the project even without the engaging top project leaders. This builds confidence in the teams. iii. Frequent delivery of products. The focus on frequent delivery of project deliverables ensures that the end-user is confident that the project is heading the right direction rather than waiting to deliver the final product which has never been reviewed by the users. iv. The focus on critical and essential deliverables. The criteria used are based on acceptance of deliverables that focus of the critical functionalities that are essential to the business at the current time of development. v. Iterative and incremental. With user involvement during the systems development process, the continuous iterative and incremental process helps in keeping check all the user requirements as the system evolves from simple to complex from to cater for the business problem in question. vi. Reversible changes during development. This sixth principle of DSDM indicates that any stage of the system development process can be reversed as long as it does not meet the user specifications. This principle increases the chances of system acceptance once the development has been completed since user requirements will have been considered throughout the development process. vii. High level scope and requirements of the project are taken as baseline before the initiation of the project. viii. DSDM integrates testing in all the stages throughout the development process of the project (project life cycle) ix. Communication, collaboration and cooperation are needed amongst all stakeholders involved in the development process. The figure below shows the process of DSDM. Figure 1: DSDM process diagram. (Stapleton). Extreme Programming Extreme programming is a software development methodology based of the fact that user requirements are dynamic and can change several times during the development process. It therefore tries to incorporate these changes in the user requirements so that the final system being developed can be largely accepted by the users. To achieve this, XP emphasizes on teamwork involvement among parties involved in the development process. (Wells) A good representation of the XP process is represented in the figure below. Figure 2: XP process. (Sauter) XP specifically prescribes active user involvement during the development process to achieve an overall success. Although this methodology one of the best since it incorporates user changing requirements during development process, the following shortcomings have been identified. a) It becomes very difficult to apply this methodology to projects with large teams. This is because agreement between teams in these kinds of projects might not be easy if not impossible. b) It is difficult to develop a full documentation during the development process due to the iterative nature of this methodology. c) User involvements into the development process mean that if not well planned, there is likely to be lots of delays in the development process. d) There is high risk of digressing away from the initial project scope if proper documentations are not put in place. DSDM versus Extreme Programming (XP) DSDM as a methodology of developing information systems share in common some of its functionalities with XP methodology. These shared practices are: i. User involvement. Both XP and DSDM engage users during the project development cycle. ii. Iterative and incremental. Both XP and DSDM involve short iterations, a process that leads to the incremental development of the project deliverables. iii. Both methodologies support good communication, teamwork and collaboration during the development process. Regardless of these similarities, these two methodologies have major differences that distinguish them from each other. The differences according to Steve Ash (Ash) are as listed below. i. In DSDM, members of the teams have been empowered to make major decision concerning the project. Although it doesn’t specify which members have been empowered to do so, XP specifies which members of the team in the project can make decision in the development process. ii. In DSDM, high-level requirements are specified to act as the baseline during the start of the project while XP embraces the notion of embracing change at any stage of the development process. It therefore means that in XP requirements of the project might change significantly during the development process. Unified Software Development Process This is methodology is used mainly in an object oriented software development environment. The advantage with this method is that it takes advantage of both the waterfall model of software development and the iterative models like the spiral model, (Computing_Students). Just like DSDM and XP methodologies of software development, USDP involves an iterative process especially at the construction level which ensures that quality of every deliverable is taken care of. This methodology has three key elements that distinguish it from other software development methodologies. These are: a) It is use-case driven. The use-cases are used to capture the functional requirements of the system and also to define the contents of the iterations. b) Architecture centric USDP insists on an architecture that acts as the baseline upon which other phases are built upon. c) Incremental development. Just like the already covered methodologies, USDP also focus on the incremental development during the project progress. d) Iterative development. This is mainly done during the construction phase of project development to ensure that quality of the system being developed is put on check. The figure below shows different processes in Object Oriented Development which is the main focus of the Unified Software Development Process. Figure 3: Object oriented development process. Just like all other methodologies, there are several shortfalls that have been identified with the USDP methodology. The following are some of them. i. USDP process is too costly to be customized for small projects. ii. Rare contact with the clients (the intended system users) thus may miss the user requirements. iii. Any change to the requirements of the system being built is always time-consuming and this might lead to the slippage of the project deadline if not checked properly. DSDM versus Unified Software Development Process (USDP) There are a variety of similarities between DSDM and USDP that can be identified before, during and after the development processes associated with these methodologies. The following are some of these similarities: i. Both methodologies focus on user involvement during the development process. ii. Both methodologies involves Iterative and incremental during the development process. The differences identified are that: i. Unlike DSDM, USDP doesn’t encourage changing of requirements during the development process leaving no room for improving quality of the system by focusing away from the initial project specifications. ii. While DSDM can be adapted in either a small or large projects, USDP is mainly used in medium to large projects since the process involved is too costly to small projects. The decision of whether to use any of the above methodologies in the project development process is determined by a variety of factor. These factors can be either of the following, combined by the preference of the development team. i. Size of the project. The size of the project is one of the determining factors for other factors. First, it will affect the budget allocated to such a project, the amount of manpower and other resources directed towards the development process. This means that the size of the project becomes a determining factor on which kind of methodology one will use in the development process. ii. How sensitive the project is. Sensitive projects tend to adopt a methodology that will cater for each details of the development. This is to ensure that the deliverables are delivered according to the specifications of the project owner. XP methodology is one of the best when it comes to sensitive projects that require focus on details of the specifications. iii. Size of the development team. The size of the team is directly related to the allocation of work during the development process of the project. When the team is small one is likely to adopt a methodology that will need less manpower (people) to accomplish a given task. A good example is the development of a hospital management software to be deployed in a several branched of the same hospital. The software is also to access a centrally located database. With this kind of project, one needs a big team to deliver different deliverables that as a whole makes up the overall system for the hospital. iv. Type of uses of the system. Projects for the development of sensitive products like software used by the military require very close scrutiny during the development and proper monitoring of the specifications. This kind of projects call for a methodology that can allow the developers to move backwards (iterations) while at the same time be on time in terms of project deadline. It is therefore important for the developers and the project owner to consider this factor while selecting a methodology to adopt for the development in their project. v. The type of the development team and their preference. Sometimes the selection of a methodology to adopt is largely determined by the type of the development team that we have. The team might be experiences in one methodology more that in another and this means that they can only adopt a methodology which they can work with and deliver well according to the requirements specifications presented to them. This factor also indicates that the project owner is limited to the methodology which his or her development team chooses to adopt. vi. The size of the budget set aside for the intended project. Methodology like the Unified Software Development Process (USDP) is more expensive compared to Extreme Programming (XP) and the Dynamic System Development Methodology (DSDM). The project owner’s ability to finance the project will also determine which development methodology he will adopt. vii. Availability of the development tools to the development team. Although not a major factor since most of the development tools are readily available in the market or the internet for downloading, whenever a given methodology requires a special tools in the development process, it means that its availability will determine whether the development team and the project owner will adopt that methodology or choose another one. It is therefore important that before choosing any given methodology, one must consider a variety of these factors and also consult with his or her development team before settling on any one given methodology. This process of selecting a methodology should be a joint action between all the parties involved directly (developers) or indirectly (project financers) in the development process. Always remember that a project’s success is determined by the kind of co-ordination and communication within the parties involved. DSDM as a methodology can effectively be used together with other development method like XP and USDP in the following ways. Since DSDM is less expensive compared to USDP, the development team can adopt a hybrid of these two methodologies and then replacing the processes that are expensive in USDP with those that are less expensive in DSDM. This will enable the development team to stay within the budget allocated to the project. DSDM can be effectively used when in small development teams compared to USDP. By considering this, the development team can effectively allocate work to the small team by using DSDM while using others advantageous features of XP methodology which focus on user involvement just like the DSDM methodology. DSDM can also be effectively be used in large project that are best suited for USDP methodology by dividing the project in to small manageable stages which as a whole is being managed by USDP but each stage being managed by DSDM. Through this, the development team and the project owner are likely to tap the advantages found in both USDP and DSDM methodologies. Sensitive projects that require careful attention to details during development but at the same time are in small budget can adopt DSDM and/or XP because of the iterations and user involvement rather than adopting USDP which will needs big budget and does not focus on the user once the development process has been commenced. There are those projects that require special tools during the development process so that the specifications of the users are kept on check. At this point if these tools are not available, the only option is to frequently involve the users during the development process so that the project does not go off track. The developers can adopt DSDM to include the element of user involvement and iterations while at the same time follow the set down requirements specifications during the start of the project by using USDP. Every software development methodology has its advantages in different development projects and the integration of different features of these methodologies during a development process can be of much benefit especially when the strong points of these methodologies have been considered. DSDM as one of these methodologies can easily integrated with others to form a rich development process for both small and large projects. In conclusion, there are several this we can achieve when we integration these tow methodology together. There are areas in which DSDM is more suitable than XP and there are areas where the vice versa is true. With these differences put in mind, a combination of best practices in these two methodologies (DSDM & XP), one is likely to gain an advantage in the development process as the shortcomings of one methodology can be improved by focusing on the strong areas of the other methodology. The same argument applies when DSDM and USDP are considered. Bibliography Ash, Steve. Compare Dsdm And Xp. 14 August 2010. 16 November 2010 . Computing_Students. Unified Software Development Process (USDP). 20 November 2010 . Highsmith, Jim. Dynamic Systems Development Model (DSDM) Methodology. 15 November 2010 . Sauter, Dr. Vicki. Extreme Programming. 2009. 15 November 2010 . Softerra. XP (Extreme Programming). 15 November 2010 . Stapleton, Jennifer. DSDM, dynamic systems development method: the method in practice. 16 November 2010 . Wells, Don. Extreme Programming: A Gentle Introduction. 28 September 2009. 15 November 2010 . Read More