Clarke, R. J (2001) S213-02: 1 Multimedia in Organisations BUSS 213 Supplementary 2 Use Cases & Descriptions

Clarke, R. J (2001) S213-02: 2 Agenda Use Cases as a Method Use Cases Use Cases and Scenarios Actor BUSS213 Example Further Reading: Whitten, J. L.; Bentley, L. D. and K. C. Dittman (2001) Systems Analysis and Design Methods 5 th Edition McGraw Hill, pp

Clarke, R. J (2001) S213-02: 3 Definitions

Clarke, R. J (2001) S213-02: 4 Definition Use Cases as a Method … use cases are generally constructed during requirements analysis but they can be used during the entire development process during the analysis phase they are used to model functionality of a proposed system and are used as a starting point for identifying the data entities and objects in a system

Clarke, R. J (2001) S213-02: 5 Definition … Use Cases as a Method … although we are using a very informal approach to use cases they can be very formal indeed- for examples in Whitten, J. L.; Bentley, L. D. and K. C. Dittman (2001) Systems Analysis and Design Methods 5 th Edition McGraw Hill, pp they are a part of the standard techniques that are used in Universal Modeling Language (UML) which is causing a bit of a revolution in Systems Analysis and Design

Clarke, R. J (2001) S213-02: 6 Definitions …Use Cases as a Method Use Cases are a technique used by analysts to clearly and concisely specify system requirements historically, the concept of Use Cases comes from object-oriented modelling (taught in BUSS211 and related subjects) it is such a useful techniques that it is also used in non-object oriented modelling an excellent technique to better understand and document system requirements can also be used in other contexts eg. user interfaces analyses

Clarke, R. J (2001) S213-02: 7 Definitions Use Case use cases are named using the name of the input preceded by an action verb eg. Finding Subject Result the primary inputs that trigger business events within the organisation or particular patterns of use (usage events) are considered use cases the external parties (often users) that provide those inputs are considered actors

Clarke, R. J (2001) S213-02: 8 Definitions Use Cases and Scenarios a use case is a behaviourally related sequence of steps called a scenario, for the purpose of completing a single business task is a description how a system (or interface, website etc) functions from the perspective of external users and in the manner and terminology they understand more than one use cases are needed to completely describe a system, interface etc. when used in traditional systems analysis, the story a particular use case describes will contain one or more system requirements

Clarke, R. J (2001) S213-02: 9 Definitions Actors use cases are started, initiated, or triggered by external users called actors represents anything that needs to interact with the system to exchange information an actor represents a role fulfilled by a user interacting with the system and is not meant to portray a single individual or job title an actor can also be an external system – not just limited to users or a role (that is a person)! an actor initiates system activity- a use case- for the purpose of completing some business task

Clarke, R. J (2001) S213-02: 10 Use Cases BUSS 213 Example… Basically the idea is to identify the audiences that might use your CD-ROM or website and write a small description- a use case scenario- showing how that user interacts with the system. For example, the UoW website serves users called Student Users (amongst others). One type of user might be called the Student (different from Prospective Students)…

Clarke, R. J (2001) S213-02: 11 Use Cases …BUSS 213 Example… An important part of the interaction between Students and UoW website is through the Student Online Services (SOL) link on the Global Navigation of the website, described in the following use case: Use Case Name: Finding Subject Result Actor(s): Students Description: In order for Students to find their marks : From UoW Home Page, select SOL Global Navigation option On loading, type in Student Identification Number (SID) Nominate which Subject they are interested in viewing.... etc

Clarke, R. J (2001) S213-02: 12 Use Cases …BUSS 213 Example Some observations: a use case only describes a small amount of system functionality the important thing is that what is described is significant for the type of user being considered there may be more one way a specific type of user interacts with the system (in fact you might worry if clients were not well served by the system) a particular scenario might be shared by two or more types of user- Student might look up ‘staff directory’ option just like Staff members