Software Development Flashcards
Agile Approach
flexible and collaborative way of working on software projects. Small manageable units of work are done on different aspects of development. Often features iteration.
Iteration
when problems are encountered you go back to a prior step or checkpoint and work through the process again
Key Features of agile approach
-frequent and close collaboration between developers and users
-Willingness to respond to changing user requirements
-producing working software early and getting feedback from users
-simplicity of design
-self organising teams
Waterfall approach
formal and linear. Different stages are completed one after another
Waterfall approach key features
-formal documentation produced at the end of each stage to inform the next
-no stage begins till the last is done
-every stage is strictly regulated
arguments for waterfall approach
-problems found early in project means they are easier and less costly to fix than if they were found later
-documentation makes process easier to understand for new team members
-progress monitored clearly
Software Development Lifecycle (SDLC)
1.Investigate / Analysis
2.Plan
3.Design
4.Create / Development
5.Evaluate / Testing
-Iterate back to 2.
6.Document / Maintenance
- Invetigate
identify and understand user and problem. Carry out a feasibility study to whether a practical solution exists
- Plan
software development plan ensures everyone understands what must happen, when and by whom
- Design
Has multiple methods (Top-down / modular). Includes protoyping and making flowcharts
Top Down Design
main system at top and breaks it down into smaller units. Each unit is further broken down until they are manageable. It’s an example of decomposition
Modular design
Main system divided into smaller units called modules. Each represents a self contained task independent of others. ONce written can by used by various parts of system
benefits of modular design
-REUSE. modules can be reused in the project and possibly others too
-SIZE. modules are relatively small so problems are easier to find and fix
-easy to UNDERSTAND
-SIMPLIFIES large projects
prototype
early version of model or product. tests concept or process and gets feedback from users. Most suitable for projects with high user interaction like an online system
flowchart circle
start / end
flowchart arrow
connector
flowchart parallelogram
input / output
flowchart rectangle
process
flowchart diamond
decision
benefits of flowcharting
-SHARED understanding on the part of team and users
-CHECKS if development process is correct
-IDENTIFY and eliminate unnecessary steps
data table
lists all data to be used and how it will be stored
variable table
variables that the software will need
user-centred design
gives top priority to the needs of the user and ensures they can use it as easily as possible. Consider UX and UD
UX
User Experience. experience of user when interfacing with a product. Includes: perception, preferences, emotion, and others. Key component is UI
UI and definition
User Interface. necessary for people to use computers. Usually a graphical interface through which the UX takes place. Can take different forms depending on design decisions
UD
Universal Design. Designing a product so everyone can understand, access and use it. Know your users to increase chance of success
UD principles 1-4
1.Equitable Use [useful for people with diverse abilities]
2.Flexability in Use [accomodates wide range of preferences and abilities]
3.Simple and Intuitive use [easily understandable to use]
4.Perceptible information [communicate necessary info effectively regardless of users sesnsory abilities
Adaptive Technology
provide features or add feature enhancements to existing technologies to aid their use for people with disabilities and older people. E.g. screenreaders, alternative keyboards, text-to-speech synthesizers
Impairment types
-Cognitive [e.g. learning]
-Visual [e.g. blindness]
-Hearing [e.g. deafness]
-Motor/dexterity [e.g. paralysis, amputation]
- Create
softare is written. System created based on previous stages. e.g. modular or topdown design. Unit testing, is normally carried out and system design may have to be modified if issues arise.
- Evaluate
Begins with software tests for errors or anything it shouldn’t do. These are usually functional tests, system tests and acceptance tests. Then a broader evaluation compares finished system with specified requirements.
Functional Testing
testing each function of a system. Can test usability, accessibility and error conditions
System Testing
Testing entire system to ensure it works as intended and meets specification agreed with client and users. Can be broken down to alpha and beta testing.
Alpha Testing
test software in house. Test as many paths through the system as possible. Discover and fix problems before users test it
Beta testing
early version of software sent to potential users for testing. Users perform tests of what would take place under real life conditions. Record problems and notify developers. Each user will use software slightly differently so they find faults not discovered in-house
Acceptance Testing
Beta testing continues until all issued raised by users are resolved. Once this has happened, the users are asked to sign off to confirm they are accepting of this software
Test data
Should include normal, incorrect, extreme and boundary values.
- Document
Keep records of communication as well as formal project documentation. Helps ensure responsibility of decisions, clear understanding, issues can be discussed between developers and non-technical staff. Saves time later when problems need to be fixed.
Typical Roles in software development
-Business Analyst
-Project Manager
-System Analyst
-Designer
-Developer
-Tester
-User liaison and training
-Administrative support
Business Analyst
- Involved from Investigate stage before rest of team is formed
- Identifies users and other stakeholders and their requirements along with the business’
- Investigates nature of the problem
- works with system analyst to produce specification of requirements
Project manager
- involved with feasability study and specification of requirements
- ensure project is delivered on time and within budget
- oversee project schedule, plan and set key dates
- resource project with staff, equipment and finance
- assign tasks related to design, implementation, testing, etc.
- communicate with and motivate team and ongoing liaison with customer
- monitor project progress
- forms project team
System Analyst
- Involved from investigate stage, before rest of team formed
- once business and user requirements identified, establish hardware and software requirements
- Investigate technical aspects of the problem
- works with business analyst to produce specification of requirements
Designer
-Design software to meet specification
-produce design documentation
-amends design documentation if necessary
Developer
-Writes programs
-maintains backup of programs
-carries out unit testing
-produces software documentation
Tester
-produces test plans
-produces test data
-carries out tests
-ensures test results are documented
User liaison and training
-ensures communication between team and users is effective at all stages
-ensures users prepared to carry out testing
-prepares training
-ensures user support is in place when system is introduced to them
Administrative Support
-Organise meetings
-Organises documentation
-Keeps track of correspondence(e.g. emails)
Factors influencing teamwork
-clarity of roles
-communication quality
-regularity of project updates
-support when things go wrong
-working environment quality
-recognition of work
-opportunity to learn as project develops
-constructive feedback from others
benefits of teamwork
-new skills and knowledge from other members
-collaborative problem solving
-developing leadership qualities
-improve communication skills
-experience of conflict resolution
-develop working relationships with colleagues
-access to support from members with problems
-job satisfaction and confidence
stakeholders
-business (the client)
-user
-general public
Use case testing
testing each possible use case(input) to ensure that each works as intended
Why SDLC is important
- structured approach reduces complexity
- minimises overrun on budget/cost
- minimises risk of missing deadlines
- maximises use of resources
- improves quality by increasing potential it will reach requirements while reducing risk of failure
Why choice of development approach is important
Enables a project to:
1. provide better estimates,
2. keep customers informed,
3. create a clear understanding of task
4. identify potential pitfalls earlier
5. allowing time to make adjustments
Example of user-centred design on a website
- Consistent page layout with a navigation at the top of every page
- Good balance of content and white space
- Good contrast between text and background
- Consistent font in terms of size and formatting
- Responsive design (works on different device types and browsers)
- Visited links change appearance
Wireframe
- Sketch diagram of webpage that shows its overall structure(navigation bar, headings, images, content, footer)
- Drawn during the design stage.
- Do not contain real content and are relatively quick and cheap to develop and modify.
Wireframe vs prototype
- Wireframe is made during design stage whereas prototype is during create
- Prototype is software whereas wireframe are just sketches
- Prototypes provide a mid to high fidelity visual representation of system whereas wireframe is low-fidelity of just one aspect
High level languages
use english like words such as while. Programs using these languages are translated into machine code using a compiler or interpreter. High level languages are machine independent
Low level languages
write code for a specific processor architecture. The language is constrained by a processor’s instruction set. Examples are assembly languages and machine code(code using 1s and 0s)
UD Principles 5 - 7
5.Tolerance for error [minimizes hazards and adverse consequences of accidental actions]
6.Low physical effort [comfortable with minimum fatigue]
7.size and space for approach and use [provides s and s regardless of body size posture or mobility]
