Transcript Lecture 6
Moving On To Design Slide 1 PowerPoint Presentation for Dennis, Wixom & Tegarden Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Key Ideas The purpose of the analysis phase is to figure out what the business needs. The purpose of the design phase is to figure out how to provide it. The steps in both analysis and design phases are highly interrelated and may require much “going back and forth” Slide 2 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Information Analysis The possible causes of the problem may be information or non-information related. Information Related Lack of or Inadequate Information Poor information quality (output as well as input) Slide 3 Relevance, Timeliness, Accuracy, Level of Detail, Format, Too much information PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Information Analysis Storage related problems Redundancy, Inaccuracy, Security, Loss of data, Inaccessible data Slide 4 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Information Analysis The analysis process should investigate the current system model and the problem statement to determine the possible causes and solutions to the problem Slide 5 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Identification of Potential Problems Storage Problems 1. any data element from a data storage used by a use case should be stored into the data storage by this or another use case. 2. any data element that is stored into a data storage should be used by some use case 3. Access of a data store directly by an external actor is not preferred Slide 6 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Problem identification Process Problems 3. any data element that comes out of a Use Case must either be input to that Use Case or generated within the Use Case 4. any data element that goes into a Use Case should either be output by that Use Case or used by the Use case to generate other data elements Slide 7 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Sample Solutions to Information Problems Inadequate information identify missing information, incorporate those in the model, may need additional process/store Inaccurate information due to incorrect processing Slide 8 identify processes whose logic are flawed, correct the flaws PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Sample Solutions due to incorrect input data incorrect input into the system, possible data collection/data entry problems, identify procedures to rectify those incorrect input generated in other parts of the system locate the source within the system and rectify it Slide 9 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Pharmacy Case Bring a printout of the UML documentation for the pharmacy case posted on the website. Go over the documentation carefully before you come to the class. Slide 10 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Functional specification document for Pharmacy 1. The system will suggest brand name and generic equivalents to customers, whenever a generic drug exists, when prescriptions are presented. The drug information presented will include the name, price, and warnings. 2. The system maintain a health history for all patients. The history will include the health as well as medications taken. Slide 11 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Functional Specs. 3. The system will maintain drug interaction information and will use it to determine whether it can fill a prescription. If negative interaction is found, it will inform the physician. 4. At the end of each month, the system will provide a list of all drugs that expired on that day, sorted according to the drug location. Slide 12 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Transition from Analysis to Design Before the detailed design, the overall architecture of the new system should be decided This involves determining the physical components of the new system Slide 13 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. How are processes handled? Automated or Manual, How many applications? Processes can also be combined at this stage. A package represents a single system that implements one or more logically connected processes within the boundary Slide 14 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Processes that are usually implemented as a single package processes that are triggered by the same event processes that use the same input processes that are temporally adjacent processes that are connected through input/output sequence Slide 15 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. How are data stores implemented? Manual, flat files, database How are data flows into the processes handled? devices such as scanner, human data entry, Voice input, Reading from a file How are data flows out of a process handled? Paper Forms/Reports, Digital Communication, Soft copy Overall architecture? Networked or stand alone system, Number of computers/printers/terminals Slide 16 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved. Design activities Input/Output/User Interface design File and database design System controls design Program (Software) design Test design Slide 17 PowerPoint Presentation for Dennis, Wixom & Tegardem Systems Analysis and Design Copyright 2001 © John Wiley & Sons, Inc. All rights reserved.