Critical Evaluation of Rich Pictures and Use Cases as a Requirements Analysis - Article Example

Critical Evaluation of Rich Pictures and Use Cases as a Requirements Analysis Tool Introduction For any process or product to be made successfully, the phenomenon of requirement analysis is very important. This is why the application of requirement analysis is commonly employed by businesses before they develop a new system or transform the one that has already been in existence. While the use of requirement analysis is very important is that it identifies the main components of a system or a process, who are generally referred to as the stakeholders, and it charts the course of their contradicting activities or actions as they work together to reach a final solution on an issue. Requirement analysis is carried out by using different techniques: one of these methods is Rich Picture. Rich Picture can be described as a graphical tool comprising of annotations and representations for different stakeholders in a system and the surrounding issues, their problems, conflicts, relationships, processes and motivation in a complicated circumstance. Peter Checkland developed this method as a way of collecting information about a complicated situation, and he termed it Soft System Methodology (Checkland 1981, p.37). Rich Picture consists mainly of three parts: structures, processes and concerns. In a system, actors are the stakeholders: these could include the end-users and other systems that operate in the environment of the main system in use. Stakeholders aren't naturally parts of the system, but their activities or actions are given optimal recognition as the system is developed. Therefore, Use Case method helps to analyse what the primary actor in a system is expected to be doing as it relates to the main system. Hence Case Modeling is generally employed in software application. Knowing fully the usefulness of Use Case could help in the application of UML and other related software development processes. Here, Rich Picture would be critically evaluated as a Requirement Analysis tool, comparing and contrasting its usages, merits and the problems that are associated with its application. Using a case study concerning a CHILD SUPPORT AGENCY, the two methods of analysis described above would be employed to highlight the principal actors in the agency's environment and the requirement expected of them. SECTION A: Soft Systems Analysis using Rich Pictures Rich Pictures emanate from the idea of Soft System Methodology (SSM), and they are used to indicate clearly how various problems, whether in the society, politics and among human being could be resolved. Concerning the CHILD SUPPORT AGENCY, the inherent "soft problems" could be identified and successfully resolved. Checkland (1990) explained that SSM comprises of seven stages: knowing the problem situation, expressing the problem situation through Rich Pictures (i.e., representations of organizational structure and processes pertinent to the problem situation), viewing the situation and producing root definitions, building conceptual models of what the system must do for each root definition, comparing the conceptual models with the real world, identifying feasible and desirable changes, to making recommendations to improve the problem situation. Below is the Rich Picture that explains the interrelationships among the main compositions of the CHILD SUPPORT AGENCY. This Rich Picture highlights the stakeholder, the structures in the system, their processes and their concerns. The Rich Picture above clearly explains the whole situation at the CHILD SUPPORT AGENCY, by outlining the major actors, their actions and what are expected of them in the suggested Management Information System (MIS). Having the knowledge of how such an Agency operates in the scenario described above would help to further understand its important expectation in the real world. The Rich Picture above shows the expected conflict, agreement and common solution to the social problem of attending to the medical needs of young, distressed people. However, the Rich Picture is silent on some important issues that would raise further questions about the operations of CSA: Like, how much influence does the Regional Director have on the entire staff as they go about doing their expected activities' Do the Funding Organisations control their cash flows, and how could such an action be taken successfully' Section B - Use Case Modelling for Requirements Analysis The Use Case analysis above paints a clearer picture of how all the stakeholders in CSA system are involved in the Agency's routine operations; it also reveals their requirements from the System in a way that individual actions are vividly defined. But the Use Case doesn't indicate how the System would respond to the requirements of secondary actors that may be affected by the actions of the primary actors. And it doesn't pinpoint the extent of executive power available to the Regional Director, while comparing his/her activities with the Chief Executive. SECTION C Critique of Use Cases and Rich Pictures ' Differences: Rich pictures are different from Use Cases in various parameters: firstly, Rich Pictures provides a pictorial network of activities or operations that occur among many actors (both primary and secondary) within a certain environment by pointing back and forth their activities, the interconnectivity of these activities and how each activity affects the other. On the other hand, Use Cases only point horizontally from one of the actors to the activities carried out by the other actors without actually reflecting the level of interaction among all the actors involved in the overall operation or activity. Secondly, Rich Pictures appear to be broader than Use Cases when presenting a series of activities; but Use Cases are more specific when referring to the information about only one of the main actors in an environment. In this case, Use Cases could furnish directly needed information about a particular actor, which may not be available in the Rich Pictures. Thirdly, the lines that originates from actions may cross each other in Rich Pictures; however, it is technically wrong to let the lines in Use Cases to cross one another: the lines are expected to be horizontal and point from the actor to the activities/operations. Use Cases Diagrams seem to itemize the contents of the activities in a chronological order: that is, it lists each operation as they occur step by step. Although this condition may not be true in all cases, however, it almost common to see Use Cases written as they naturally occur. On the contrary, Rich Pictures' constituents are scattered all over the model with no appreciable chronology. Another conspicuous difference between the Rich Picture and Use Case lies in how the actors are classified. Rich Pictures divide the actors into primary and secondary ones, while Use Case employs the use of only the primary actors in a system. ' Usefulness of Rich Pictures and Use Cases: There is no doubt that both the Rich Pictures and Use Cases are useful tools for requirements analysis process. This is possible in the sense that they present clearly the premise of an activity by highlighting the actors, their actions, and the environment at which they operate. Rich Pictures present multiple actors and their activities at the same time, while Use Cases describe the activities performed or that affected a few number of actors. The functions of both analysis tools include: qualitative and quantitative analysis. Qualitative analysis concentrates on the quality of actions or activity each other actors committed, and how it influences each actor in the network. In the example, one may ask the following questions about quality: How accurate is the personal/health information about the admit patient' Was the system of collecting the data error-free' How did the clerk know what to do' Did he/she have enough training for the job' How about the quality of the treatment at the ward' Are the nurses qualified' And how effective are the activities of both the on-call doctor and the consultant team' It is possible for the answers to the above quality control questions be displayed on either the Rich Pictures or the Use cases. In the area of qualitative analysis, both the Rich Pictures and Use cases reveal something about the number or amount of issues involved in the processes. Take for example, both the Rich Pictures and Use Cases above indicate how many actors, their number of activities, and how much influence they have on one another. This is very important because it gives the real picture of the actors and prevents any thought of bias or unclear circumstances. Without the use of a Rich Picture or a Use Case Diagram, it is unlikely that modeling would be understandable to those who have no knowledge of design in computer science. But Rich Pictures and Use cases simplify the scenarios and make them understandable even to a layman. ' Is there a connection between these two approaches' The connection between these two approaches for requirements analysis lies in the fact that they are both analytical tools. And they exhibit similar characteristics in the following ways: (a) Structure: Both approaches indicate the structures in a scenario. For example, the structures in the Case Study above are ward/bed, system, clerk, on-call doctor and consultant team. All these actors are unique and fixed: they could not be easily removed as far as this scenario is concerned. (b) Process: Both the Rich Pictures and Use Cases describe the processes happening in an environment. For instance, the supply of personal/health information by the admit patient is a process; and the processing of the supplied information to determine what level of medical treatment to allot to the patient is also a process. So, each of these two approaches explain what is happening, from which actor and for what purposes. (c) Pictorial in nature: both of the two approaches employ the use of pictures (pictorial images) that would convey clearly the identities of the actors involved in the activities. Without this, it would be very difficult to identify who is doing what in a particular setting. (d) Use of appropriate language: Each process in both Rich Pictures and Use Cases applies the appropriate language that goes with the scenario. Like when discussing about medical treatment, the mention of health information, doctor, ward/bed etc are related expressions for this circumstance. (e) Interdependency: To some people, Use Cases are separate parts of a Rich Picture put together. While this may appear so in certain condition, however, Use Cases seem to describe in greater details the activities carried out by an actor in a scenario. So, this interdependency is one of the commonest connections between the Rich Pictures and the Use Cases. (f) Scaling the models: both the Rich Picture and Use Case models' scale could be reduced or expanded: In this sense, they could accommodation some indispensable transformations all along the modeling process. (g) Stakeholders'concerns: There is no doubt that both the two techniques of requirements analysis take into serious consideration the concerns or the tasks to be accomplished by the stakeholders. For example, the above Rich Picture and Use Case Diagram reveal all the primary actors and state in clear terms their individual concerns that are undertaken in the environment. This makes it easy to decode the aspect of responsibility of each actor in the system. CONCLUSION It is obvious that both Rich Picture and Use Case diagram of the Case study distinctly present the true requirements in an environment of CSA, and outlined the responsibility of actions each actor (primary or secondary) in the System'It has been argued in support of these analytical tools that a system might run into poor performance if the components of the system lack neatly defined scope of action , which, in a way could lead to interlocking of problems within the system. However, the Rich Picture above reveals that each actor has an activity to carry out, and they do so in concurrence with the others' responsibilities so as to seek a common and lasting solution to the problems available at CSA. The two analytic methodologies are cheap, and could be done within a short period of time. In other words, one could always adjust the criteria for these analysis techniques until a perfect Master's plan is achieved. To obtain a very useful information about CSA, one needs to visit the agency and talk one-to-one with the principal actors that know the ins and outs of the environment where the company operates. REFERENCES Checkland, P. (1981), Systems Thinking, Systems Practice. John Wiley & Sons, Chichester. Checkland, P. (1990), Soft System Methodology in Action. Toronto, Ontario, Canada: John Wiley & Sons. Read More