Tuesday, August 20, 2019
Structured Systems Analysis And Design Method Information Technology Essay
Structured Systems Analysis And Design Method Information Technology Essay Structured System Analysis and Design method is a framework that adopts Structure approach to the analysis and design of the information systems alike previous structured methods such as Yourdon in 1976,DeMarco in 1979 . It is sequential development process called as waterfall method. It was produced for Central Computer and Telecommunications Agency (CCTA) and also the UK government now known as Office of Government Commerce (OGC). In 1981 UK government was taken this method as a compulsory for all projects but since then the other countries and some private organization used it greatly (Ashworth et al, 1995).SSADM supports the developers and project managers in understanding four questions they are What is to be done, When it is to be done, How it is to be done, Where the resultant inform is to be documented (Bentley et al, 1995).Some history of this methodology since 1980, Central Computer and Telecommunications Agency determines the analysis and design methods. In the year of 1981 Learmonth Burchett Management Systems (LBMS) method has chosen from shortlist of five. In the year of 1983 SSADM made mandatory for all new information system developments. Version 2 of SSADM was released in 1984. Version 3 of SSADM was released and that was adapted by NCC in 1986. After 1988, SSADM certificate of Proficiency launched, SSADM promoted as open standard. Version 4 of SSADM has released in 1990. (Websites: http://www.dcs.bbk.ac.uk/~steve/1/tsld005.htm). This is a wide methodology and also flexible to apply at any kind of problem situation. It divides the works or projects into distinct units (Downs et al, 1992).SSADM is a basic assumption that systems have an underlying, generic, data structure which changes very little over time (Ashworth et al,1990). The SSADM version 4 has formed five important frames such as, Feasibility Study (FS), Requirements Analysis (RA), Requirements Specification (RS), Logical System Specification (LS) and Physical Design (PD). This five-module framework has seven stages and each stage has explained exactly with their own strategy, controls, and activity, this helps the main purpose of the project management technique (Avison and Fitzgerald, 1995; Downs et al, 1992). Diagram: The Feasibility Study (FS) is first module of the methodology; it holds the position of stage 0, this phase has four steps: First one is prepare for study to know measurement of evaluation of the project; then define the problem by using comparison between requirements with current position; selection of Feasibility from among others; the final one is to submit a report of the Feasibility. Data flow diagram and flow documents are used in this technique (Avison and Fitzgerald, 1995). Requirement Analysis (RA) is one of the most important stages of SSADM. This involved with describing the requirements of information systems. This is a fundamental level for business purpose. It has two stages; a major aim of the first stage is to make understand fully about the system for analysts. Analyst should investigate the feasibility of the project if before stage was not done and also the problem situation should be described by using data models and data flow models; Interviewing to the employees and users also included in this stage. The second one is Business System option; during this stage the analysts would determine such business system options by group actions for their customers. The previous stage has named that, a business system option is a potential solution to the system requirements. This includes boundaries of the solution and inputs and outputs. Requirement Specification (RS) is a single stage and it makes over the description of the current environment and business system option which was made by Requirements Analysis. Clients of this system would select business option at the end of RA. During this stage analysts should combine the investigation of all the stages results from 1 to 3 by keep the business option, to develop a specification of the system. It also describes actual function of the system. Entity-event modelling and rational data analysis are the techniques used in this stage. During the stage 3, various models of the system are being developed such as, Data Flow Model (DFM) and Logical Data Model (LDM).This stage brings details the DFM and LDM. The function definition has unites into one for specification process design at this stage. The next module, Logical System Specification (LS) has two stages in it. Such as stage 4 and stage 5, Technical System Option considered as stage 4 and Logical design as stage 5. Technical System Option is the final stage for analysis phase and conversion to the literal system design. Many execution chances are suggested to select nearly suitable solution similar to stage 2. This technical system options are measured by financial cost and performance of the system and limitations etc. After the stage 4, Logical Design took place as a stage 5, the works and investigation has been done as same like before stage. The main execution of Logical Design is about human factor. It defines dialogue and updates enquiries in non-procedural manner, which is independent of any implementation strategy. Physical Design (PD) is the final module of this system. It is the best choice of possible technical and logical solution, the designer combines the result of the previous stages to build the final aim of the system. This is stage 6 and outcomes in PD for the data and processes (Ashworth et al, 1990, Bentley et al, 1995, Downs et al, 1992). The above essay tells that, SSADM has a well-defined structure and easy to understand by everyone. Many of the UK University has taken this information system in comprehensively and completely. These models and diagrams are giving complete definitions for the final users and developers to understand (Ashworth et al, 1990, Avison and Fitzgerald, 1995). ETHICS (Effective Technique and Human Implementation of Computer-based Systems) Ethics methodology came up out of work started by Enid Mumford at Manchester Business School in 1969. Since then, it has been used in industries and the health services. Much experience gained from these usages (Mumford, 1997). Ethics is acronym, but this approach is to represent the ethical position. This is the information system development, which strongly supports the human participation (Avison and Fitzgerald, 1995). This methodology is well-known for its importance and interest in the human side of systems design (Jayaratna, 1994). It includes the socio-technical view for the system to be effective and this technology should be applicable for social and organisational factors. It also means that a valuable quality of working life and increased job satisfaction of the users is one of the major objective of this system design process. Mumford determines the essential quality of socio-technical approach as one which recognizes the interaction of technology and people and produces the work systems which are both technically efficient and have social characteristics which lead to high job satisfaction; and job satisfaction as the attainment of a good fit between what the employee is seeking from his work-and his job needs, expectations and aspirations-and what he is required to do in his job-the organisational job requirements which mould his experience(Avison and Fitzgerald, 1995). To determine the concept of fit is used to describe the job satisfaction in five fields: Firstly, knowledge fit as a good fit lives when employees should accept that their skills are being adequately utilized and their knowledge being improved to make them efficiently; Physical fit is the second area that means; job must suitable for the employee status, encouragement of the progress and work interest; thirdly efficiency fit, it composed of the effort-reward bargain, work controls and supervisory controls; fourthly the task structured fit, that measures the level to the employees task are considered as being fulfilling and demanding; and the final area is ethical fit, this is also represents social value fit and determines whether the employer organisation be compatible with values of employee(Avison and Fitzgerald 1995). Ethics is a methodology that based on human participation and socio technical character. The Ethics design group consist of users, managers and technical experts. The objective of this methodology helps the design group in the way of identifying and formulating the problem, and also it will set objectives and develop alternatives, and allow other actions like implementing and evaluating new system. It aims to construct the computer based system that provides job satisfaction and achieve the efficiency needs of the organisation (Jayaratna, 1994). During this development, the importance placed on both the human and social and the technical views of the system. Users formulate social alternatives to improve job satisfaction, and experts formulate technical alternatives to improve business efficiency. The above aspects are emphasis to identify the best socio-technical fit under the common cost, resource and other environment constraints (Wong, 2001). Here, the ETHICS steps are executed by the design group: Why change? By enquiring about the problem situation of the current system, design group try to get objective through regular meetings and some discussions to answer the question: why do we need to change. This step gives clear reasons about why the changing system needed (Mumford, 1993). System Boundaries. The design team tries to identify the boundaries of the system and also how it is interfaces with other system. Description of Existing System. This step aims to educate the design group to know how the existing system works. Everyone in this group has more comprehensible of previous system before moving to the new system. 4, 5 and 6 Definition of the key objectives, tasks and information needs. Identify the key objectives for the design groups; the task required to achieve these objectives and information is needed to carry out the tasks. 7. Diagnosis of Efficiency Needs. The design group tries to identify the weak link in the system and that is to be documented. These are main reason for errors. Everyone outside the team help to identify the efficiency need. This could be the opportunity for the team to get involved in the development process. 8. Diagnosis of Job Satisfaction Needs. This is achieved by the standard questionnaire given in the ETHICS methodology. As we know earlier ETHICS is a human-cantered method for others to gain the job satisfaction. The design team tries to identify people needs and also ways to increase satisfaction by using ETHICS questionnaire. This questionnaire covers knowledge fit, physical fit, efficiency fit, task structured fit and ethical fit. 9. Future Analysis The new system need to be designed in the way that apart from just being better from previous system, it should also be able to cope with future changes that may occur in the technological, business and organisation or fashion. 10. Specifying and weighting Efficiency and Job Satisfaction Needs and Objectives Mumford identifies that this is the key step for the whole methodology. Objectives are set according to the diagnosis results of the three previous steps. It can be very difficult task and must involve everyone in the organisation. 11. Organizational Design of the New System. This is the logical and conceptual design of the new system. It should be performed in parallel with next step. The output of this step is detailed about the organizational changes which are needed for the job efficiency and satisfaction objectives. 12. Technical Options. The physical design has been taken by this step for new system. There are some various technical systems like hardware, software and GUI would be investigated and evaluated. By end of this step, most suitable one helps to achieve target of the project and job satisfaction. 13. Preparation of Detailed Design Work. In this step the selected system is designed in detail. The previous documentation is recorded and groups are defined, tasks, responsibilities are allocated and finally relationships are created. 14. Implementation. This is the important step of the development project. The design group now applies the success implementation of design. This connects closely to planning the implementation process in detail. 15. Evaluation. After the successful implementation, the system is assured it is meeting its main objectives, particularly in relation to efficiency and job satisfaction (Avison and Fitzgerald, 1995, Mumford, 1993). Mumford recognizes that implementing this methodology is not an easy one; also she is making the addition point that participative may not work at the powerful situations where the objectives of the system have as a part of the reduction of cost and redundancies. Aylors and Myers suggest that participation may be achieved will be dependent on culture and politics of the organisation more than individuals (Avison and Taylor, 1995). However, many organizations are trying to establish the participation approach in flexible and more useful manner. The comparison between two methodologies (SSADM ETHICS): As we said in the introduction before, we will do comparison between two methodologies mentioned above by using NIMSAD (Normative Information Model-Based System Analysis and Design) framework. These methodologies are compared in detail by using the different steps. This framework consists of three steps and one of the steps contains eight stages fewer than three phases and all the stages steps are correctly evaluated. The steps and stages of the framework will be explained below, The Problem Situation (the methodology context). The Intended Problem Solver (the methodology user). The Problem Solving Process (the methodology). Phase 1- Problem Formation: Stage 1- Understanding the situation of concern. Stage 2- Performing the diagnosis. Stage 3- Defining the prognosis outline. Stage 4- Defining Problem Stage 5- Deriving notional systems. Phase 2- Solution Design: Stage 6- Performing the conceptual/logical design. Stage 7- Performing the physical design. Phase 3- Design Implementation Stage 8- Implementation of design. Evaluation. Problem Situation: This framework will be involved with clients and defines different between the action world and thinking world. This step explains that the problem situation lives in only on action world but the problem solving situation will be in both world. A diagrammatic model cannot catch the elements of an organisation, but they could be used to clarify the concepts and components. This clearly tells that the problem solvers own knowledge and skills will not help to understand the problem situation unless he/she know the organisational language (Jayaratna). In Ethics, the problem situation of the existing system is clearly analysed through the regular meetings and proper discussion. This step could be a main cause for the system change plan. The boundaries of the system have been identified by the design group and also they try to determine how boundaries are connected and communicated with other system (Mumford, 1993).When compare to Ethics, SSADM investigate and study about the problem situation and they will confirm the position from user. These results are explained by the data flow diagram Diagram of problem solving situation: Intended Problem Solver: The intended problem solver is who originate within the organisation or outside of it. We have begun to discuss about the agreement of role and the act of forming relationship to be effective. The NIMSAD framework explains that the intended problem solver adds the single man component to the process and their Mental Construct is used. In Ethics, after the analysis process, this step shows that the design group is been educated about the problem which will make them clear view of the existing problem situation. The main aim of the problem solver is to achieve the job satisfaction and efficiency needs. But in SSADM, the problem solver is fully trained and skilled. They will not get any advice like Ethics and have to understand the problem and find the solution of their own. Diagram for the intended problem solver: Problem Solving Process: NIMSAD defines three important phases and eight detailed stages in this step and can be applicable for any problem solving process. This framework cannot be assumed and this should be achieved at the right time. This methodology could be structured process to alter transformation from current situation to the desired situation. Phase 1.Problem Formulation: Stage1.Understanding the Situation of concern: Understanding the problem is fully based on each one of our mental construct. This stage will build boundaries to determine the field of interest and clear communication of boundaries to avoid danger and this focused on investigation and establish concerned situation. In Ethics as mentioned above, the problem situation is identified. After that the boundaries are set accordingly for evaluating the problem. Then the designer will start gathering the points to solve a problem. In SSADM, the problem is been assumed as a data flow diagram and this will be used to solve the problems. So they will start making points to evaluate the problems. Stage2.Perfoming the Diagnosis: Diagnosis is clearly communicated expression of understanding and that is gained from investigating the problem situation. This is a static expression and also identified by the tool for problem solver or prescribed by the methodology. Mental construct and situation concern are the dynamic process of the expression. Action World cannot be represented by only in diagrammatic way but, it can be a certain priority for the problem solver. In Ethics, diagnosis is to identify the weak link which creates errors and make a document of them for future use. The weak links are the reasons for errors in the system. Everyone from outside can help to determine the efficiency needs. This will be an opportunity for them to get involve. Ethics is human-centered method and its aims to get job satisfaction from each of the employers. A new system should be developed or designed for to cope with the future changes. Diagnosis is a big opportunity for the whole management to get involve for the result (Mumford, 1993). In SSADM, the developers have not been advised or educated to cope the problem situation. The designers should know what the system actually need and they should study and decide about problem. The designers will keep the current records and previous documents Stage3. Defining the prognosis outline: Prognosis pointed a diagrammatically by various outline shape and also it is a desired situation. The prognosis outline compares the current situation with desired situation for to identify the problem. This stays only in outline rather than elaborated. It is presented in few methodologies because, this is an intellectual and political skills. Ethics problem situation has been done in various outlines, and the designers will get feedback from others or inside of the organisation to handle the situation as much as possible. In SSADM, problem elements of the existing system could be chosen by the user among some options like business. Analyst should design the system requirements for how the users exactly want. Stage4.Defining Problem: After clarifying the before stages rationale, the problem solver can look at the system prevention from moving from current to desired state. It will try to find the explanation of problem statements. This process defines that the problem looks at the mapping of two comprehended states. Jayaratna defined that this process is critical and identify the absence of the aspects and this must be based on some form of questions what and why, not how and whom. In Ethics, the design team tries to determine the way to increase the job satisfaction by asking questions. There are some key steps involved in this step as mentioned in before stage. Everyone from the organization must get involve for the development process. In SSADM, the problem cannot be solved by simply looking and thinking as prognosis does. So result of the feasibility study should be combined by the analyst with business option. Stage5.Deriving Notional Systems: Notional system is achieved after completing the Diagnosis to Prognosis as current to desired situation by mapping for to defeat the identified problems and alter the transformation. This model allows the structured problem situation and that can be unstructured or ill-structured and this may be difficult to find. In Ethics, prefers no diagrammatic representation for the changing process. All the design group and analyst will be educated and advised properly for the development process to get good results (Mumford, 1983). SSADM, it is a validating necessary step for the user. The data flow diagrams are used to achieve the actual model of the system requirements. There will be priority for the users need and also feedbacks after increasing prototype for next process. Phase2. Solution Design: Stage6.Perfoming the conceptual/logical design: Diagnosis model is basis for the creation or change of structures, roles, task, functions, information and attitudes of the notional system. This stage is also providing a chance for to re-evaluate the previous stage. In this event, the boundary situation and its contents are considered. In Ethics, the job satisfaction is achieved by the modification from result of this stage. This stage will study that, this is been done by the logical design for developing the system. SSADM use the data flow diagrams for all of the logical design techniques. The designers will perform their operation by changing the diagrams according to the requirements and guidelines. This organisation of system checks the requirements for the system development process. Stage7. Performing the Physical Design: The physical design provides the ways and entails of implementing the logical design. It also points that physical constrains and resources available to implement the logical design. The physical design is regarded with two questions to perform, how it could be done and who is going to do this. The criteria of the physical design determine the decision of the appropriate model, such as Efficiency, Reliability, Security, and Accuracy, upgradeability and Availability, etc. In Ethics, this stage is followed by the logical design. It is investigated and evaluated using the hardware, software, and GUI. In order to achieve the design of the system. In SSADM, the physical design checks whether, it reaches the users specification or the needs of the developing system. Then the system is passed to the programmer from the developer and from here the implementation of the system begins. Phase 3.Design Implementation: Stage8.Implementatoin of the design: It is concerned with the organization of the notional system inside the context of the problem situation. The writing code practice and requiring knowledge and skill in itself, is the component of the implementation process. The competence at translating model from thinking world to action world will be the tested in the implementation stage. Ethics plays vital role in the implementation of the design. The design group complete the entire system and produced to user, then gets the feedback from user. If there are any changes in the developed system, they have to restart the entire system. This is considered as a main drawback in this method (Mumford, 1993). When compare to Ethics, SSADM is well organised, because in this methodology the design group explains the system in each and every stage and then proceed to the forthcoming stages. Evaluation: The entire purpose of NIMSAD framework is evaluating all the methodologies. Evaluation is nothing but asking question, so this framework concerned with the user for to ask questions from the first three steps for the evaluation process. Then the problem solver will ask questions related to the problem situation, then their own the mental construct and experience will be taken for the evaluation. In Ethics, this is the final step of the methodology after completing the implementation part. This evaluation process checks whether the system is achieved the job satisfaction and efficiency needs which is the main objectives of the system. When compare to the Ethics, SSADM does not give more importance to this stage, because it will get feedbacks from the user at each and every stage. Conclusion: There are lot of essential differences between the SSADM and ETHICS as we have looked in the previous sections. The ETHICS methodology aims to attain balance between the designers and available technologies. It provides good opportunity for the developers to work in flexible, highly co-operative environment. Some people believe that ETHICS is impractical because, unskilled cannot design in the right manner and management never take that. The socio-technical approach is the solution for problem situation. As we discussed earlier, ETHICS will not be the right solution like other methodologies, it has both negatives and limitations. The people should trust themselves and try to learn the system to achieve great job efficiency. Every organization attains the profit and business objectives by the combination of job satisfaction and job efficiency. As we discussed earlier, SSADM is a structured subsystem and this will be one of the main reason for easy understanding and studying the system and also causes for well-defined subsystems. The final users and developers can understand the exact definitions through diagrams and models. SSADM is a growing development method and it helps to distinguish the physical and logical parts of the design. The final users of the SSADM involves in the development process. It gives an idea about to use different techniques of this framework such as how, why, when, and where. It gives three various system views for the developers (Ashworth et al, 1990).
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