A consideration of utmost importance for enterprise system designers, managers, and auditors is the consideration of risk and control. The objective of this chapter is to introduce some types of risk that occur in enterprises and discuss how these risks may be lessened by controls designed into enterprise information systems. This chapter uses the REA pattern as a framework for identifying types of risks and controls to mitigate those risks. | Lecture 8 Enterprise Systems Development ( CSC447) COMSATS Islamabad Muhammad Usman, Assistant Professor College of Statistical and Acturial Science 1 Use Case Modeling What is a Use Case? Narrative descriptions of domain processes in a structured prose format They are stories or scenarios of how people use the system A Short Example to Start With Dice game A software simulates a player rolling two dice. If the total is seven, they win; otherwise, they lose. A Short Example to Start With Use case: Play a game Actors: Player Description: Player requests to roll the dice. System presents results: If the dice face value totals seven, player wins; otherwise, player loses. 5 Case Study – The NextGen POS System Computerized application used to record sales and handle payments Used in retail store It includes hardware and software It also interfaces to other applications, such as a third-party tax calculator and inventory control Multiple and varied clients-side terminals and interfaces Commercial POS 6 Use Case, Actor, and Scenario Actors Something with behavior such as person, computer system, or organization Scenario It is a specific sequence of actions and interactions between actors and the system. It is also called use case instance It is one particular story of using a system . scenario of successfully purchasing items with cash or scenario of failing to purchase items because of credit payment denial Use case then is a collection of success and failure scenarios Use cases are requirements, primarily functional. 7 Use Case, Actor, and Scenario A UC is a dialogue between an Actor and a system that accomplishes a task. The dialogue is presented as a sequence of steps A complete sequence of steps is a use case scenario A scenario (UC instance) forms a complete path thru the UC. 8 Use Case, Actor, and Scenario UC can contain multiple scenarios (., >1 path thru UC) Can range from simple (brief summary) to elaborate (detailed steps using adopted document . | Lecture 8 Enterprise Systems Development ( CSC447) COMSATS Islamabad Muhammad Usman, Assistant Professor College of Statistical and Acturial Science 1 Use Case Modeling What is a Use Case? Narrative descriptions of domain processes in a structured prose format They are stories or scenarios of how people use the system A Short Example to Start With Dice game A software simulates a player rolling two dice. If the total is seven, they win; otherwise, they lose. A Short Example to Start With Use case: Play a game Actors: Player Description: Player requests to roll the dice. System presents results: If the dice face value totals seven, player wins; otherwise, player loses. 5 Case Study – The NextGen POS System Computerized application used to record sales and handle payments Used in retail store It includes hardware and software It also interfaces to other applications, such as a third-party tax calculator and inventory control Multiple and varied clients-side terminals and interfaces .
