Chapter 9 Decisions in Business areas The Strategic Management of Information echnology
Chapter 9 Decisions in Business Areas The Strategic Management of Information Technology
Transaction Processing System Input Process Output Software Design Systems Development Communication Information
Transaction Processing System Input Process Output Information Communication Systems Development Software Design
Database Types Hierarchical Network Relational
Database Types Hierarchical Network Relational
Hierarchical Tree Diagram Node Parent Parent Child Child Node Node
Hierarchical Tree Diagram Node Parent Parent Child Node Child Node
Architecture Program Database Indexing ocking Files Files Performed Performed Local File File Workstation File Server Server Server Client File Database Database Database Server Server Server Server Server
Architecture Program Database Indexing Locking Files Files Performed Performed Local File File Workstation File Server Server Server Client File Database Database Database Server Server Server Server Server
Normalized Record Type 1. Which of the methods yields"better results? 2. Which of the methods is easier" to use? 3. Which of the methods is preferred by the participant?
1. Which of the methods yields “better” results? 2. Which of the methods is “easier” to use? 3. Which of the methods is preferred by the participant? Normalized Record Type
Three Hypotheses H1 Performance/Quality-In pursuing simple design tasks the quality of the results would be better with normalization whereas in complex design tasks the quality would be better with IA H2. Time- Normalization would require less time to perform than IA, irrespective of the complexity of the task involved H3 Preference - Designers would prefer the normalization method over the la method
Three Hypotheses H1. Performance/Quality - In pursuing simple design tasks the quality of the results would be better with normalization, whereas in complex design tasks the quality would be better with IA. H2. Time - Normalization would require less time to perform than IA, irrespective of the complexity of the task involved. H3. Preference - Designers would prefer the normalization method over the IA method
Database Definition a collection of information on a well defined subject that is exhaustive nonredundant, and structured Exhaustive: database contains all data about the subject Nonredundancy: no data element is stored twice to insure consistency Structuring the data: storing data to make processing efficient
Database Definition – A collection of information on a welldefined subject that is exhaustive, nonredundant, and structured. Exhaustive: database contains all data about the subject. Nonredundancy: no data element is stored twice to insure consistency. Structuring the data: storing data to make processing efficient
Key Project Steps Preliminary Functional Specification What is the current situation? What should be obtained functions printouts, results of queries data to be stored for future reference Improvements Who should benefit from the new application? How much can the organization afford to pay? When are the results required /what schedule is considered? What will be the new information flow? What will the user activities be? What volumes of transactions are considered?
Key Project Steps Preliminary Functional Specification – What is the current situation? – What should be obtained? functions printouts, results of queries data to be stored for future reference improvements – Who should benefit from the new application? – How much can the organization afford to pay? – When are the results required/what schedule is considered? What will be the new information flow? What will the user activities be? What volumes of transactions are considered?
Key Project Steps Detailed Functional Specification Screen Dialog Screen and printout contents Data dictionary Logical groups or files Data integrity and consistency constraints Processing constraints Lists and cross-references Test data lustrations of data and logic To check that the specifications described actually work To provide user acceptance criteria for the future software To provide complete training cases for future end users
Key Project Steps Detailed Functional Specification – Screen Dialog – Screen and printout contents – Data dictionary – Logical groups or files – Data integrity and consistency constraints – Processing constraints – Lists and cross-references – Test data – Illustrations of data and logic – To check that the specifications described actually work – To provide user acceptance criteria for the future software – To provide complete training cases for future end users