Evaluating Methods on the Basis of NIMSAD - Term Paper Example

 «Evaluating Methods on the Basis of NIMSAD» Table of Contents Executive summary……………………………………………….…………….3 Overview of NIMSAD Framework………………………………………...…..3 Methodologies selected for evaluation……………………………………….…6 The SSADM methodology…………………………………………………...….6 The SSM methodology………………………………………………………..…8 Applying the NIMSAD Framework……………………………………………9 Discussion of results…………………………………………………………….13 Conclusion……………………………………………………………..………..13 References…………………………………………………………..…………..15 Executive Summary Evaluation of software architectures with regard to their quality, responsiveness and performance attributes has been proposed through various methodologies. However, using a point of view method for evaluation is suggested in very little frameworks. NIMSAD (Normative Information Model-based Systems Analysis and Design) Framework is one which allows the identification of similarities and differences between methods on the basis of their context, users and structure. This paper attempts to discuss the NIMSAD framework and its subsequent application in comparing and contrasting two system methodologies- SSADM (Structured Systems Analysis and Design Methodology) and SSM (Soft Systems Methodology). Separate sections have been dedicated to provide an outline of both the methodologies to provide a base of understanding for the readers. Consequently, NIMSAD has been applied to evaluate the methodologies and differentiate between them, followed by a discussion of results and concluding remarks. Use of diagrams has also been done to anchor the technical aspect understanding of systems, methodologies and the processes. Overview of NIMSAD Framework NIMSAD (Normative Information Model-based Systems Analysis and Design) is a reflective and problem based framework meant to evaluate system design and analysis methodologies. It not only allows critical evaluation of the entire experience, but also facilitates the user to learn from the conclusions and recommendations. It takes in its purview the background of the problem, the problem solving process and the stakeholders involved in the methodology (Fig. 1). Fig. 1: The NIMSAD Framework Source: http://www.emeraldinsight.com/content_images/fig/1310100407002.png Four major components constitute the NIMSAD Framework (Reichgelt 2006, p.274) which is briefed as below: The problem situation The factors which govern the context and perception of the problem situation are covered under this element of the framework. This element being dynamic in nature provides a number of interpretations and possibility of conclusions. Different sub-factors involved in this element impart variety in the problem situation thereby altering its characteristics and attributes. Those sub-factors are processes, people, information flows, materials, structures and technology. Thus, numerous interrelationships are formed which are essential to be understood to arrive at a rich and broad picture of the entire problem situation. It also defines the stakeholders involved and the probable contribution they are supposed to make. Higher knowledge of this element will facilitate the user in gaining better understanding of the problems entailed. The intended problem solver This element takes note of the role, responsibility, stake and contribution factors in the problem situation. It refers to groups or individuals who not only assess the problems but also formulate the main problem and also derive conclusions and solutions. The users here can be directly or indirectly associated with the problem situation but they have some sort of role to play and something at stake in the problem. Here personal characteristics of the users help them perform well and execute their roles properly. In this regard, some major personal characteristics of intended problem solvers are values, experiences, motives, skills, knowledge, reasoning ability, perception, prejudices, ethics and other models and frameworks. These personal traits guide the intended course of action of the problem solvers and help them assess, learn, judge and act on specific situations. The problem solving process With inputs from the problem situation and the characteristics of the intended problem solvers, this element decides upon the approach to be adopted to solve the problem. It is structured in its format as it contains three sub-phases with eight activities intact (Fig. 1). This format provides a systematic outlook to the framework with output of one sub-phase becoming the input for another sub-phase. PHASES STAGES 1. Problem formulation Understanding the situation of concern Diagnosis Outline definition Problem definition Deriving notional systems 2. Solution design Logical design Physical design 3. Design implementation Design implementation Fig. 1 Evaluation This is the last but the most important element of the framework as it undertakes critical evaluation of the other three elements discussed above. This evaluation takes place in three stages- before, during and after. Maximizing effectiveness is the sole objective of the evaluation before intervention. Managing all the involved entities regulates the evaluation during intervention while drawing lessons from the actions and their subsequent contribution constitutes the focus of evaluation after intervention. Methodologies selected for evaluation NIMSAD framework is considered suitable for evaluation of methodologies pertaining to systems design and analysis as it takes into account both the hard and soft issues and is considered to be less subjective than other approaches. It majorly reviews the dynamic interconnections between managerial, human and technical interfaces of a problem solving methodology which imparts it greater significance as to its applicability to the problem situation. In this paper, the two methodologies selected for evaluation, comparing and contrasting on the basis of NIMSAD framework are SSADM (Structured Systems Analysis and Design Methodology) and SSM (Soft Systems Methodology). Subsequent detailing of the methodologies and their comparison has been covered in upcoming sections. The SSADM Methodology The SSADM (Structured Systems Analysis and Design Methodology) is a waterfall model based methodology (Malcolm n.d) meant specifically to address long term business situations of government and other Information Systems institutions. Its focus areas are quality, human resources and communication flows in a systems design method for solving a problem. SSADM is comprised of five steps (Malcolm n.d) which are sequential in nature and can be further broken down. Those five steps are: Feasibility study Factors favoring the conception and continuance of the system are determined in this study. It involves time, cost and effort constraints which might hamper the system to continue further or pose problems in later stages of development. Their intensity is also judged to prioritize the list for action formulation. Requirements analysis What requirements the system poses are identified in this analysis through a process-by-process approach. Modeling of requirements can also be done to tailor the needs of the system. Requirements specifications This section takes on its initial information from the above analysis and elaborates that input in detail. The requirements are segregated into functional and non-functional and also in technical, managerial and other categories to facilitate allocation of cost, time and effort. Logical system specification This element involves creation of logical design of the system and identifying technical options to fulfill the goals. Last stage design elements namely enquiry and update components are also designed in this step. Physical design Inputs of logical and technical design from the previous step bring out the physical design as the output of this step. Database and program specifications are also created in this step. Documentation forms an integral part of all the five steps. Coupled with rigorous requirements analysis, SSADM offers the benefit of tailoring the system according to the needs of different users and also maintains the quality both before and after the completion. However, over-emphasis on these two processes results in disadvantage also as it leads to cost and time wastage. Failure in maintaining consistency and possibility of unclear goals also arises due to continual change in the objectives of the system initially developed. The SSM Methodology Authored by Peter Checkland and John Poulter, SSM (Soft Systems Methodology) is an approach to address soft issues of a complex business situation. Where there are divergent views in a situation and it is difficult to formulate a problem which is agreed upon by all, SSM allows development of debate in such conditions. The set of activities which provide a sequence to the SSM are (Reynolds, Holwell & Holwell 2010, p.20): Structuring the problem situation and identification of players and processes. Expressing problem situation through organizational processes and management technologies. Applying root definitions and the CATWOE technique (Fig. 2) (Hopkins 2009, p.160) to the core activities of the system. Conceptual models defined in a minimum number of activities. Comparison of real world and model is undertaken. Changes are designed. Action steps for improvement are thought of and implemented. ROOT DEFINITIONS C “Customers” of the process- either the beneficiaries or the victims A “Actors” of the process T “Transformation Process” itself depicting conversion of input to output W "Weltanschauung" or assumptions which make the system workable O “Owners” who are authorized to stop the process. E “Environment” putting constraints on the system Applying the NIMSAD Framework As discussed, the two selected methodologies are being evaluated on the basis of NIMSAD framework. All the steps of the framework namely the methodology context, methodology users and methodology problem solving are being used as stages for the evaluation. Contrasting the methods and discussion of results will be based on the evaluation conclusions. Evaluating SSADM Problem situation While evaluating the problem context of SSADM, it has been observed that organizational context owns greater preference over other components in SSADM. It is more formal in its nature with focus on data flow diagrams. While conducting the feasibility study, this methodology checks the commitment of users which is a good practice in assessing the role of the users involved. However, due to over-prioritized organizational context, changing patterns are not properly addressed in SSADM. Problem solver SSADM focuses on technical skill set of users more than their social ones which limits their mental construct and the ability to make effective methodology. Also, SSADM allows its users to come out with different sets of data flow diagrams and patterns thus providing different options to the system (Comparison of Methodologies n.d). Problem solving process Stage 1: SSADM makes use of trial and error method in constructing the boundary of its problem which lefts out some components which cannot be covered in DFDs. Everything is arrived at by data flow diagrams. Stage 2: this is the most contributive stage of SSADM which seeks to develop physical data flows and logical data flow model of the system. However, again due to different mental constructs, arriving at logicalization is problematic as information which is regular gets updated while non-frequent information is ignored. Stage 3: in this stage, it is assumed that the ultimate user knows what it wants and so they are free to choose among business system options (BSO) (Comparison of Methodologies n.d). Stage 4: problem definition is more of explicit as there is no clear demarcation between diagnosis and prognosis stages. Thus, points are still unclear in this stage also. Stage 5: this is again the strength portion of SSADM where requirements are formalized through DFDs and modeling. Prototype is developed which helps getting the feedback from the client. Stage 6: DFDs are the most powerful tools in the logical designing in SSADM. The feasibility study works as the guidelines and DFDs help develop the dialogue also. However, it does not take into account how these design decision will affect the environment as it only pays attention to requirements. Stage 7: physical design is mostly guided by technical issues of the system which leaves scope for non-technical areas of design and thus, is a hampering factor in SSADM problem solving process. Stage 8: implementation is overall missing in SSADM which can be considered as one of the weakest points of this technique as a problem solving approach. Evaluation Evaluation is once again absent from this methodology which eliminates the chance of personal evaluation and monitoring of the methodology. Thus, it cannot be established as to whether everything has moved according to the chalked out plans and designs or not. Summary All in all, SSADM fails to cover the ‘soft’ aspects of Information systems development along with missing implementation and evaluation phases. It is more formalized with inadequate attention to non-technical components of the system. Evaluating SSM Problem situation Being a soft systems structured approach, it takes into account different views of a single ill-structured problem. It also identifies three types of roles in its problem context- the problem solver (person who resolves the concerns), the problem owner (person who identifies systems) and the client (person who initiates the problem). These three roles impart different viewpoints and perceptions to the problem context (Comparison of Methodologies n.d). Problem solver The methodology user in this methodology is able to reflect its learning and perception through its mental construct which goes by the NIMSAD framework. The users here are both learners as well as facilitators. Problem solving process Stage 1: understanding the situation of concern is a rich picture process in SSM owing to three types of roles which provide contributions to the entire context and help in the development of a good and broad boundary construct. Everything is open to questioning by others users which helps eliminate doubts and confusions and provide clarity to the systems objectives. Stage 2: diagnosis stage is not restricted to data flow diagrams but charts, graphs or any other format can be used by the users which facilitate their understanding. With freedom comes lot of responsibilities to the users as they need to know what they are supposed to do and how. Also, there is no differentiation between logical and physical designing components of diagnosis. Stage 3 and Stage 4: defining and describing problems in SSM are conducted at later stages which is different from SSADM and also not conventional like other structured methodologies. Because of different viewpoints provided by different users and root definitions, SSM fails to address a clear prognosis definition. Thus, there are clients who are not clear and sure of the desired states. Stage 5: root definitions or CATWOE are used to define notional systems in SSM which is a new technique altogether. Stage 6 and Stage 7: logical design and physical design stages are merged in SSM with no demarcation between the two. SSM does not focus much on designing aspects of systems development and here also, CATWOE guides the little bit of designing process that is in place. Stage 8: implementation like SSADM is missing here also. Evaluation Evaluation is not an obvious step in SSM. However, users are encouraged to learn and promote learning through the use of SSM case studies like Information Systems Planning and Health Care (Comparison of Methodologies n.d). Summary SSM is more suited to problems which come through different viewpoints and cannot be defined in a single problem statement. SSM allows criticism on those viewpoints and constructive debate to refine those critics. The process of refinement is continuous in SSM as users and participants keep on presenting their views and opinions. Discussion of results After evaluating SSADM and SSM on the basis of NIMSAD, there are many points which come out as differences between the two methodologies. Those points of differences are: Paradigm: in SSADM, greater focus is on hard thinking and scientific form of paradigm where use of reductionism and repeatability is widespread. On the contrary, SSM is more focused to soft thinking and systems approach of paradigm with orientation towards interrelationships between different parts of the entire system. SSADM makes use of data flow diagrams majorly in its diagnosis and problem solving process. DFDs are not applicable in all types of situations and thus, SSADM cannot fit well is all kinds of problem contexts. Contrasting, SSM is better suited to organizations with human interactions and activity situations in majority as SSM assumes more roles and responsibilities than SSADM. Data flow diagrams make SSADM a rigid kind of methodology with little or no possibility of incorporating changes and modeling it. However, this is not the case with SSM as it gives the freedom to choose any kind of technique for diagnosis, prognosis and problem definition. Thus, it gives vent to a flexible and rich picture formation. Regarding the roles assumed in both the methodologies, SSADM keeps its users in their traditional code of conduct whereby analysts and designers do the stereotypic roles. In SSM, the clients are entrusted with greater understanding of their roles and duties and providing solutions to the problem owner. Conclusion All in all, it can be said that while SSADM takes more of its knowledge and references from commercial background, SSM does so through academic ones. SSADM is also more documentation and output oriented which is not so in SSM. Hard and soft thinking approach is the biggest differentiator between these two methodologies and it is the point which determines the applicability of the methodologies in diverse business situations. References 1. Comparison of Methodologies n.d. Retrieved 11 Nov, 2010 from http://www.dcs.bbk.ac.uk/~sven/cdm07/cdm13.pdf 2. Eva Malcolm n.d. SSADM Version 4: A User’s Guide. McGraw Hill. 3. Hopkins, B. (2009). Cultural Differences and Improving Performance: How Values and Beliefs influence Organizational Performance. England: Gower Publishing. 4. Reichgelt, H. (2006). Measuring Information Systems Delivery Quality. USA: Idea Group Publishing. 5. Reynolds, L, Holwell, S & Holwell, S. (2010). Systems Approach to Managing Change: A Practical Guide. UK: Springer London. Read More