Intro to Systems Analysis and Modelling
Categories:
What is System
There are two jobs mainly for system
- achieve goals
- MOST IMPORTANTLY add value to existing system
A system generally contain 2 character, user and developer. Developer can get value from user and user needs will accomplished from system
For programmer build a system using code. before writing they need a plan.
SDLC
This is the MAIN concept of modelling requirement and analysis, which is the key part of hole lesson. we will talk deeply in later chapter
the workflow called Systems Development Life Cycle (SDLC), it’s a process of gradual refinement Each phase consists of a series of steps and Each phase is documented (deliverables) Phases are executed sequentially, incrementally, iteratively or in some other pattern
This 4 phase is BASIC concept, a common view is during entire develop life, developers should review and revisit in multi times, when and in which order?
Project Methodology
https://www.virtasant.com/blog/sdlc-methodologies
SDLC Methodologies are processes and practices used by software development teams in order to successfully navigate the Software Development Life Cycle (SDLC).
let’s skip old-fashioned methodology
Throwaway-Protyping
building initial ideas for different applications, interfaces, or functions, without necessarily having the intention of including them in the finished system.
the idea is to gather feedback, prove concepts, or undertake other research tasks.
Agile
Agile is the mainstream methodology used in modern software development The Agile methodology breaks a project down into multiple cycles, each passing through some or all of the SDLC phases.
Scrum
Scrum Framework provided a Practical way of Agile
kanban
kanban is another framework of agile
Kanban is a scheduling system framework, Kanban has a host of benefits when applied to Agile. You can limit WIP, focus on cycle time, and utilize just-in-time practices.
Kanban is sometimes compared to Scrum, which are similar in some ways, but are distinct frameworks:
- Scrum utilizes fixed length Sprints cycles while Kanban is about continuous flow
- Scrum is role focused, while Kanban doesn’t utilize roles
- Scrum measures velocity, while Kanban focuses on cycle time
Extreme Programming
Planning Phase
Process and Document in Planning phase
Planning Phase - Current we focus on Initiation
- system request
- feasibility analysis
System Request
A document that describes the reasons for and the value new system will add
This is the first step in the SDLC process
phases on System Request
Let’s get clearify here
- Who recommend to build - sponsor
- Why to build - business need
- What the build provided - business requirement
- What value build provided - business value
- Other
Notice: This is non-technic focus, emphasis on business aspects
Examples:
business need:
business requirement
business value
Feasibility
Once the need for system is finished, Project need more detail file
Time is a management issue, We ignored here Most team revise study during SDLC and revisit content at every check points Team may cancel the project or create substantial revisions
Technical Feasibility
- familiar business application area
- familiar with the technology, delay will cause when learning new technology
- project size
- compatibility, most cases we build a system on existing system
The assessment of a project’s technical feasibility is not cut and dried. In many cases, some interpretation of underlying conditions is needed
- one is to compare prior projects undertaken by orgnization
- another is to consult with IT professionals or external it consultants
Examples:
Business area
familiarity with technology
project size
compatibility
Analysis Phase
Required Gathering
The most critical step for SDLC. when trying develop a system. Good method of requirement gathering can prepared
high vs. low requirement
Techniques within Requirements-Gathering
Lab & Exercise 1
Documenting Lab1
Overview: A wealthy entrepreneur and art lover has decided to create an online system called ArtSpace, to assist in the display and sale of works of art. She has employed you to create a design for the system. The system is intended to bring together a range of different user groups who are interested in art sales and purchases: artists; art dealers; serious art buyers and collectors; and casual members of the public who may consider buying art works on occasion.