Systems Design & Analysis

Stakeholder: A person who has an investment, share or interest in a business.

A stakeholder is anyone who:

• Operates the system
• Benefits from the system (function, politics, finances, social benefits)
• Is involved in buying or taking control of the system
• Regulates and takes care of finances, safety and other aspects of the system.
• Opposes the system (negative stakeholders)
• Is responsible for subsystems of the system

Observation - Monitoring a system while it is at work

Focus Group - A group of people/stakeholders are gathered together and questioned on their opinions towards a project or product

Surveys - A data colection used to gather information about individuals

Interview - face to face meeting, consisting of the interviewer asking the interviewee questions that are pertinent to the topic of the interview

Observing the current system - Observing the user's workflow, inputs and outputs can provide info as to how the system works and how it can be improved.

Looking at competitive software - analysing what they have included and to what extent they have an effect on the solution.

Interview users - can get personal feedback and suggestions for improvement, stakeholders will be able to tell you hwat they want to get out of the new system.

System flow charts - displays how data flows in a system and how decisions are made to control ouptut:

• diamonds = decisions
• rectanlges = processes
• rhombus = input/output
• arrrow = data flow direction

Data flow charts - similar to SFCs but do not show decisions (applies to the simbols as well), only data paths, where it is held and where it is processed

Structure charts - shows the breakdown of a system to it's lowest managable modules. Aids programmers in dividing the software into sub problems.

• box = module in the system
• arrow = connection or ownership between modules

Prototype: An original type, form or instance serving as a basis standard for later stages

Benefits:

• The software desinger and implementar can get feedback from users early in the project
• The client and contractor can check if the software made matches the specification set by the client
• The software engineer has insight into the accuracy of initial prohect estimates and whether the deadlines will be met

The process of prototyping:

1. Identify basic requirements - incl input and output info required
2. Develop initial prototype - includes only user interfaces
3. Reviews - customers/end-users examine the prototype and provide feedback
4. Revise and enhance prototype - using feedback, specs and product are improved. Scope of contract/product may be negotiated.
5. IF chnages are made, REPEAT steps  3 & 4

• finds problems quickly - easy to try it again
• problems which many test users had are noted
• solutions are tested to make sure problems are solved
• finds new usability problems by the new chnaged design
• teaches that continual failure leads to a more successful final product
• can save money
• enables objective assessment of the project's status
• inconsistencies among requirments, design and implementations are detected early

If the requirements of the end user are not met the system will have no purpose.

Conseuquences:

• lack of feedback during the design process
• lack of stakeholders willing to provide resources
• dissatisfaction from end-users as needs may not be met

In order to meet requirements of the user, the designer must consider these questions in the deisgn stage:

• How much disk storage will the master file consume?
• How many lines of program code will it take to perform this function?
• How can we cut down on CPU time when we run the system?
• What are the most efficient ways of storing this data?
• What database management system should we use?

• Reliability & Integrity - operation of hardware, design of software, accuracy of data or correspondance of data with the real world. Data lacks integrity when it has been changed accidenty or tampered with. Example: info is duplicated in a relational database and only one copy is updated
• Security - protection of hardware, software, machines and networks from unauthorised access. Security measures include restricted access to machines and networks for certain employees to prevent hacking
• Privacy & Anonymity - the ability for individual and groups to determine how when and what info is shared about them with others. Privacy can become anonymity for cyber-bullying & digital criminals.
• Intellectual property - ideas, discoveries, wriitngs, works of art, software, collections and presentations of data. Digital duplication methos undermine protection of intellectual property
• Authenticity - establishing a user's identity beyond resonable doubt, crucial in business & legal matters.
• The digital divide and equality of access - disparities exists between countries & socio-economic groups -> some are left disadvantaged
• Surveillance - Use of IT to monitor the people's actions eg. track/record/assess employee's performance

• Globalisation and culutural diversity - dimishing of geographical, political, economic and cultural boundaries. IT has reduced these boudnaries by making events and people more accessible
• Policies - enforcable measures inteded to promote appropriate use of IT by organisations
• Standards and protocols - technical rules and conventions that enable compatibility & communication between different IT systems
• People and machines - Many jobs don by humans are now done by computer systems. Social impacts such as internet addiction
• Digital citizenship - appropriate behaviour that represents the responsible, ethical and legal approach that indiividuals take in regards to IT. Permeates social & ethical considerations.