Structured System Analysis and Design Method - Literature review Example

?STRUCTURED SYSTEM ANALYSIS AND DESIGN METHOD Structured System Analysis and Design Method Affiliation Introduction Structured systems analysis and design method (or simply SSADM) is one of most popular software development approach that is widely used in the UK. In fact, in the UK its practice is frequently mentioned as a requirement for government sector computing projects. In view of the fact that this software development methodology was developed for the CCTA, which is a UK government office deals with the use of technology in government, from 1980 onwards for this reason it is more and more being followed by the public sector projects and organizations in Europe. Additionally, this methodology is believed to be a public domain, as well as is officially represented in British Standard BS7738. Basically, software development methodologies are a most important element of the software development sector which aspires to offer a structure for action and to gather, store, process and distribute information in an attempt to support the economic growth of information systems and software development that are well for purpose. In this scenario, structured systems analysis and design methodology is a kind of linear sequential process model through which software systems are designed and developed. Additionally, this methodology is considered as a representation of a pinnacle of the thorough document-led mechanism to design a software system, and differ with modern RAD (Rapid Application Development) approaches for instance DSDM (Samyal, 2013; Rouse, 2008; Patel, 2005, p. 75). In addition, one of the most attractive features of this software development methodology is that it divides a software development project into several manageable components, steps, stages and activities, and offers a mechanism for defining projects in a way that is easy to manage and control. Some of the major objectives of SSADM methodology are outlined below (Rouse, 2008; Samyal, 2013; Schumacher, 2001): Provides management team with effective control over the software development process Allows software development firm to make more effective use of skilled and new development personnel Facilitates software development team to build high quality systems The loss of staff does not affect the progress of projects Encourage use of computer-based tools for instance computer-aided software engineering systems Establish and maintain a structure for effective communications and collaboration between stakeholders in a project Moreover, this software development technique effectively manages all the aspects of software development life-cycle varying from the phase of a feasibility study for the actual software development. Additionally, many software development firms use this methodology in association with various other approaches, for instance PRINCE and PRINCE2, which is effective in dealing with various activities of project management. In addition, this software development methodology forms a flow or a waterfall vision of software development, which is based on carrying out a series of steps, and all these steps are interrelated. Some researchers contrast it with the RAD model as it pre-supposes a need to conduct steps autonomously. As discussed above, structured systems analysis and design method divides the software development process in various stages which are outlined below (Rouse, 2008; Samyal, 2013; Schumacher, 2001): In the first step a detailed feasibility study is done to determine the feasibility of a project. Analysis and study of the current environment In this step different business system options are identified At this stage system requirements are defined This step involves identifying various system options At this stage logical design of the system is developed Last stage involves the development of a physical design Furthermore, for every phase, structured systems analysis and design method forms a set of procedures, techniques and rules for communicating and recording information pertaining to these both in diagrammatic and textual form. Without out a doubt, structured systems analysis and design method is widely used software development approach, and a feature of this methodology is that projects can use simply those components of SSADM which are suitable for the project’s needs and requirements. In the same way, SSADM support a large number of CASE tools (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Advantages of SSADM Helpful in meeting Deadline: In view of the fact that SSADM follows a series of steps hence all the activities are planned and managed in a systematic way. In this scenario, software development team can effectively plan, schedule, direct and have power over a project well. In addition, once all the steps are followed sequentially a team can complete the project on time (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Takes into Consideration Usability Aspects: It is an admitted fact that structured systems analysis and design method pays particular attention to the detailed study and analysis of user needs. At the same time, the systems model is built as well as a detailed demand analysis is conducted. The basic purpose of implementing both these analyses is to see whether they are compatible to each other (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Effective in dealing with changes in the business environment: In view of the fact that in structured systems analysis and design method, documentation of the project’s development is believed to be a critical software development activity, hence issues related to business needs as well as business objectives are taken into consideration all the way through the software development process. In this scenario, it is helpful in making changes to project plan according to the authentic requirements of the business (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Does not require Extensive Skills: Software development team does not need to have high level skills and knowledge in order to adopt structured systems analysis and design method for the reason that it does not require particular knowledge and skills and can with no trouble be taught to the team members and stakeholders. As discussed above, it provides an excellent support for CASE tools which are easy to use for designing systems. In addition, a wide variety of commercial CASE tools are also available with the purpose of establishing SSADM easily (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Deliver High Quality Results: Without a doubt, structured systems analysis and design method minimizes the chances of errors in system development by describing a definite quality level in the early stage of software development and continuously monitoring the system (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Enhanced efficiency: structured systems analysis and design method surely improves the overall efficiency of both project team and organization for the reason that it ensures in time project completion, ensures high quality, complies with business requirements, and makes use of human resources efficiently and effectively (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Minimizes software development costs: In view of the fact that structured systems analysis and design method separately develops both the logical and the physical systems design hence the software development team does not need to implement again with new software or hardware (Rouse, 2008; Samyal, 2013; Schumacher, 2001). Disadvantages of SSADM As discussed above, structured systems analysis and design method pays special attention to the system analysis and its documentation. Without a doubt, too much analysis and documentation are time-consuming processes. When the time for software development increases it surely increases the cost. In addition, because of several types of explanation techniques, it is difficult to carry out regular consistency checks. Particularly, when the size of the system is huge, the description of the system through diagrams can turn out to be vague, for the reason that all applicable data flows need to be mentioned in the diagrams. In addition, this methodology is completed in a series of sequential steps so when a change takes place software development team might have to repeat all these steps that are also a time-consuming task. On the other hand, large software development firms which complete a large number of projects can take benefit of the fact that structured systems analysis and design method provides them with an opportunity to reprocess and repeat definite tools and techniques for other projects. In this scenario, they can diminish the time and cost spent extremely in the long run (Samyal, 2013; Hughes & Cotterell, 2002). Software Development Phases A discussed above, structured systems analysis and design method represents a waterfall view in which there is a series of steps that execute in a sequence and the completion of one step leads to initialization of the next step. In addition, SSADM is divided into five phases which are outlined below: Feasibility study: The first phase of SSADM is a feasibility study in which a precise analysis of the system is carried out in order to determine the feasibility of the project. At this stage, software development firm decided whether this project is feasible or not and they should accept this project or reject this project. Requirements Analysis: After accepting a project, the next stage is to analyze the requirements and business needs of software development project. In addition, at this stage software development firm also models these requirements in terms of the processes carried out. Requirements Specification: After analyzing system requirements a detailed analysis is carried out to determine the functional and non functional requirements of a system. At this stage requirements are checked for completeness and consistency (Kotonya & Sommerville, 1998). Logical System Specification: At this stage technical system choices are developed and the logical design of the system is developed. This logical design encompasses the design of inquiry and update processing. Physical Design: This is the last stage of SSADM where the logical system specification and technical system specification are utilized to develop a physical database design and along with a set of program specifications. In addition, for each of the above discussed phases structured systems analysis and design method offers procedures and techniques for communicating and recording the information in both textual and diagrammatic forms (Samyal, 2013). Key techniques used in SSADM Normally, there are three techniques used in SSADM, which are outlined below: Logical Data Modelling: This technique allows us to identify, model and document the data requirements of the system being designed. However, in order to uniquely identify data this is divided into several entities and relationships between these entities established (Whitten, Bentley, & Dittman, 2000; Samyal, 2013). Data Flow Modelling. This technique allows us to differentiate how the data will move around all the way through the information system. At this stage we can develop a data flow diagram to represent data flow within the system. The basic purpose of a data flow diagram is to show the flow of data from one entity to another. It also represents the storage and processing of data. Basically, data flow diagram is a very useful way for describing a system. In fact, these diagrams are used to describe the system at any level of point with a picture containing a wide variety of symbols representing data stores, data flows, data sources/destinations and data processes. In this scenario, the data flow diagrams are very useful in building a semantic bridge between systems developers and users. In view of the fact these diagrams allow system developers to represent system working using diagram so they eliminate thousands of words. Additionally, these diagrams provide logical representations, representing what a system does, instead of physical models showing how the system does. They are helpful to users who want to gain an understanding of the system. However, the basic purpose of data flow diagrams is to present a frequently understood model of a system. In fact, these diagrams are believed to be the foundation of structured systems analysis and design. In this scenario, data flow diagrams can also be supported by a number of other methods of structured systems analysis for instance data dictionaries, data structure diagrams, and procedure-representing methods for instance decision tables, structured English and decision trees (Kozar, 1997). This technique allows us to analyze system processes, external entities, data stores and data flows (Samyal, 2013; Schumacher, 2001). Entity Behavior Modelling: This technique is aimed at determining, modelling and documenting activities regarding the entities in the system as well as the sequence in which these activities are carried out. In this scenario, an entity relationship diagram is used to demonstrate the relationship between entities and the nature of their relationship. In addition, an ER diagram is a graphical depiction of various data types through conventions that explain how these data are associated with each other (Nishadha, 2013; Samyal, 2013; Schumacher, 2001). Inputs and Outputs of SSADM As SSADM operates in a series of steps so each step takes specific input and gives specific output. For instance, at the stage of feasibility study an analysis will be carried out to determine the feasibility of the project. In this scenario, inputs will be standards, rules, processes and procedures that an organization adopts to accept or reject a project and the output of this phase will be a feasibility report, which will be used as a basis to make a decision. In the second phase, a requirements analysis is carried out for which input is a feasibility report and output of this phase is a draft document. In addition, this draft document and previous system’s manuals work as inputs to the next stage and the output of this stage is a software requirements specification document, which outlines the detailed requirements. Moreover, this SRS is provided as an input to the next stage and logical system design is developed as an output. In the same way, on the basis of this logical system design a physical design of the system is formed (Kotonya & Sommerville, 1998; Kotonya & Sommerville, 1998). Above we have discussed the inputs and outputs generated at different phases of SSADM. Now we will discuss the inputs and outputs of SSADM on the whole. Figure 1Inputs and Outputs of SSADM, Image Source: (Goodland & Riha, 1999) Figure1 outlines the inputs and outputs of SSADM. In this scenario, SSADM takes two inputs: Project initiation document and reports generated in result of previous studies. Project initiation document further includes: business case, terms of reference, project boundaries and project management. On the other hand, other part includes feasibility report and IS strategy report. Basically, project initiation document is a huge document which contains a lot of data regarding project. It includes the scope of the project, project management approach, and the whole business scenario. In addition, SSADM takes these documents to generate various outputs including: program specification, database specification, user procedures and operations procedures. SSADM takes into consideration the inputs provided by different documents and in the light of these documents the development team develops database design, establish requirements for programming, and define what actions will be performed by the users and what procedures will be required to perform those operations (Goodland & Riha, 1999). Conclusion This paper has presented a detailed analysis of structured systems analysis and design method. This methodology is believed to be one of the most effective software development approaches. This paper has discussed some of the important aspects associated with this development methodology. This software development methodology divides the system analysis and design process into a series of sequential steps. However, this methodology is believed to be a very formal process as it emphasis on documentation. Though, in the large project's documentation and detailed analysis are very effective but in small projects they become time consuming and costly. However, like other software development methodologies this is just a way to design a system but it depends on skills software development team how effectively they make use of this methodology. References Goodland, M., & Riha, K. (1999, January 20). SSADM - an Introduction. Retrieved March 03, 2013, from http://www.dcs.bbk.ac.uk/~steve/1/sld007.htm Hughes, B., & Cotterell, M. (2002). Software Project Management. (3rd ed.). Glasgow: McGRAW-HILL Publishing. Kotonya, G., & Sommerville, I. (1998). Requirements Engineering Processes and Techniques. New York: John Wiley and Sons. Kozar, K. A. (1997). The Technique of Data Flow Diagramming. Retrieved March 03, 2013, from http://spot.colorado.edu/~kozar/DFDtechnique.html Nishadha. (2013). Diagrams. Retrieved March 02, 2013, from http://creately.com/blog/diagrams/er-diagrams-tutorial/ Patel, N. V. (2005). Critical Systems Analysis And Design: A Personal Framework Approach. New York: Routledge. Rouse, M. (2008, March). SSADM (Structured Systems Analysis & Design Method). Retrieved February 26, 2013, from TechTarget.com: http://searchsoftwarequality.techtarget.com/definition/SSADM Samyal, V. (2013). Structured Systems Analysis and Design Methodology. Retrieved February 22, 2013, from http://vijaysamyal.tripod.com/SSAD.pdf Schumacher, M. (2001). The use of SSADM (Structured Systems Analysis and Design Methodology) as a standard methodology on Information Systems Projects. Retrieved February 24, 2013, from http://www.grin.com/en/e-book/106034/the-use-of-ssadm-structured-systems-analysis-and-design-methodology-as Whitten, J. L., Bentley, L. D., & Dittman, K. C. (2000). Systems Analysis and Design Methods 5th Edition. New York: Irwin/McGraw-Hill. Read More