1. Systems Design, Implementation, Maintenance, and Review
Chapter 13:
Systems Design, Implementation, Maintenance,
and Review

2. Agenda Systems Design Systems Implementation Systems Maintenance
Systems Review
Systems Performance Measurement

3. Systems Design
A phase in the development of an IS system that answers the question “How will the information system do what it must do to obtain a solution to a problem?”
Logical Systems Design describes the functional requirements of a systems.
Physical Systems Design specifies the characteristics of the system components necessary to put the logical design into action.

4. Logical Design Elements
Output design describes types, format, content and frequency of all outputs from the system
Input design specifies the types, format, content and frequency of input data
Processing design defines the manipulation required for processing
File and database design specifies files and databases (i.e., ER diagrams)
Telecommunications design (i.e., topologies)
Procedures design to operate the system
Controls and security design (i.e., disaster recovery)
Personnel and job design (i.e., job titles, positions)

5. Physical Design Elements
Hardware design specifies all computer equipment
Software design specifies all software capabilities
Database design specifies the type, structure, and function of the database
Telecommunications design includes the characteristics of the communications software, media, and devices
Personnel design specifies the background and experience of individuals
Procedures and control design specifies how each application is to run and what has to be done to minimize the potential for crime and fraud

6. Design of Procedures for Signing On
Sign-on Procedures are safeguards needed for an individual to gain access to computer resources
Systems Sign-on allows user to gain access to the computer system
Application Sign-on permits the user to start and use a particular application

7. Design for Interactive Processing
People interact directly with the processing component of the system
In menu-driven systems, users pick what they want to do from a list of alternatives
Help Facility is a tool that aids a user who is having difficulty understanding what is happening or what type of response is expected
Restart Procedures are procedures that make it very simple for an individual to restart an application from where one left off
Lookup Tables are tables within an application that simplifies and shortens data entry

8. Design for Interactive Dialogue
Dialogue is the series of messages and prompts communicated between the system and the user. These design elements should be considered during systems design:
Clarity
Response time
Consistency
Format
Jargon

9. Design for Preventing, Detecting, and Correcting Errors
Best time to deal with potential errors is at the beginning of design rather than in the late part of design, or during implementation.

10. Design for Emergency Alternative Procedures and Disaster Recovery
Disaster Recovery is the implementation of the disaster plan.
Hardware Backup
Hot Site is a duplicate computer system that is operational and ready for use
Cold Site (Shell) is a computer environment that includes rooms, electrical service, telecommunications links, data storage devices
Software and database backup
Selective backup copies of only certain files
Incremental backup copies all files changed during the last few days or the last week
Image Log is a separate file that contains only changes to applications
Telecommunications backup
Personnel backup
Security, fraud, and the invasion of privacy

11. Systems Controls
System controls are procedures to maintain data security and can help prevent:
Computer misuse
Crime
Fraud
Deterrence Controls are rules that prevent problems before they occur (input, output, processing, telecommunication, personal controls)
Information system departments are closed shops when only authorized operators can run the computers
In open shops, non-operators, such as programmers and systems analysts, are authorized to run the computers

12. Evaluation Techniques
In Group Consensus, a decision-making group is appointed and given the responsibility of making the final evaluation and selection
Cost/Benefit Analysis lists the costs and benefits of each proposed system
Benchmark Test is an examination that compares computer systems operating under the same conditions
In Point Evaluation, each evaluation factor is assigned a weight, in percentage points, based on importance; the system with the greatest total score is selected.

13. Design Report
The Design Report reflects the decisions made for system design and prepares the way for systems implementation. 22

14. The Value of Investment in Design41

15. Systems Implementation
Systems Implementation includes:
Hardware/Software acquisition or development
User preparation
Hiring and training of personnel
Site and data preparation
Installation
Testing
Start-up
User acceptance. 23

16. Financial Options to Acquire Systems
Advantages
Disadvantages
Buying
Cheaper than leasing or renting
Ability to change system
Tax advantages
Full control
High initial cost
Risk of obsolescence
Risk of being stuck if choice is wrong
Full responsibility
Leasing
No capital is tied up
No financing required
Leasing is cheaper than rental
Do not own system
Heavy penalty for terminating lease
More expensive than buying
Renting
Easy to change systems
Maintenance and insurance usually included
Cost is high

17. The Make-or-Buy Software Decision
Building Own Software
IS educated staff
Buying Software
Review needs of requirements
Acquire software
Modify or customize software
Acquire software interfaces
Test and accept the software
Maintain the software and make necessary modifications 24

18. Programming Life Cycle
Programming Life Cycle is a series of steps and planned activities developed to maximize the likelihood of developing good software:
Language selection
Program coding
Testing and debugging
Developing documentation
Implementation or conversion 26

19. Documentation Technical Documentation User Documentation
Used by computer operators to execute the program and by analysts and programmers in case there are problems with the program or if the program needs modification.
User Documentation
Developed for the individuals who use the program. This type of documentation shows users, in easy-to-understand terms, how the program can and should be used. 27

20. Tools and Techniques for Software Development
Structured design breaks a large, difficult problem into smaller problems, each simple enough to manage and solve independently
Structured Programming a way of developing code that provides structure within the program so that testing and maintenance tasks are facilitated.
Object-Oriented Development is the development of a collection of existing modules of code or objects than can be used across any number of applications without being rewritten.
Computer Aided Software Engineering (CASE)
Cross-Platform Development allows programmers to develop programs that can run on computer systems having different hardware and operating systems
Integrated Development Environments (IDEs) are software packages that combine the tools needed for programming with a programming language into one integrated package
A Structured Walkthrough is a planned and pre-announced review of the progress of a program module, a structure chart, or a human procedure

21. Types of Testing Testing of individual programs.
Testing the entire system of programs.
Testing the application with a large amount of data.
Testing all related systems together.
Conducting any tests required by the user.

22. Start-Up Approaches Start-Up Approach
Procedures that begin with the final tested information system; when start-up is finished, the system will be fully operational.

23. Reasons for Maintenance
Systems Maintenance involves checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals.
Changes in business processes
New requests from stakeholders, users, and managers
Bugs or errors in the program
Technical and hardware problems
Corporate mergers and acquisitions
Government regulations
Change in operating system or hardware on which the application runs 38

24. Type of Maintenance
Slipstream Upgrade is a minor upgrade not worth announcing.
A Patch is a minor change to correct a problem or make a small enhancement.
A Release is a significant program change that often requires changes in the documentation.
A Version is a major program change, typically encompassing many new features. 39

25. Maintenance Costs as a Function of Age

26. Systems Review
Systems Review is the process of analyzing systems to make sure they are operating as intended.
An Event-Driven Review is triggered by a problem or opportunity such as an error, a corporate merger, or a new market for products
A Time-Driven Review is a review of all systems that is performed after a specified amount of time. 42

27. Systems Performance Measurement
Systems Performance Measurement is a systems review that involves monitoring the system -- the number of errors encountered, the amount of memory required, the amount of processing or CPU time needed, and other problems.
System Performance Products are products developed to measure all components of the computer-based information system, including hardware, software, database, telecommunications, and network systems. 44

28. Systems Development Alternatives
Request for proposal
Vendor evaluation
Reliability
Financial stability
Service
Maintenance
Training

29. Points to Remember Systems Design Systems Implementation
Systems Maintenance
Systems Review
Systems Performance Measurement

30. Pop Quiz
Name the design to describe the functional requirements of a systems.
Name the design to specify the characteristics of the system components.
Name the design to specify the characteristics of the communications software, media, and devices.
Name the procedures to safeguard the access to computer resources.
Name two backup methods for hardware equipments.
Name three backup methods for software programs and database.
Name the evaluation technique using a evaluation factor based on the importance.
Name three financial options to acquire systems.
Name the review triggered by a problem or opportunity.
Name the systems review to monitor the system.

31. Pop Quiz Answer
Name the design to describe the functional requirements of a systems. Logical
Name the design to specify the characteristics of the system components. Physical
Name the design to specify the characteristics of the communications software, media, and devices. Telecommunication
Name the procedures to safeguard the access to computer resources. Sign on
Name two backup methods for hardware equipments. Hot site, cold site
Name three backup methods for software programs and database. Selective, incremental, image
Name the evaluation technique using a evaluation factor based on the importance. Point evaluation
Name three financial options to acquire systems. Buy, lease, rent
Name the review triggered by a problem or opportunity. Event driven
Name the systems review to monitor the system. System performance measurement