Intro to Systems Analysis and Modelling

Categories:

• School

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.

What is Systems Analysis and Modelling?

Programmers need to know what to write.

They can not just write as ‘I THINK’

a large assignment need cooperation and need required that everybody understand clear and no confusion. Most IMPROTANT, we need find a way providing value to ognization by meeting requirement from user.

To accompish that , programmer need follow rules

• identifying the problem that needs to be solved
• analysing the current situation (resources or evidence needed to find a solution)
• identifying requirements for the new system(requirement from user)
• modelling those requirements in a systematic way
• creating a clear specification all above

Let’s leave a question here ==Q: What is modelling?==

as you may asking, is it all about design a system?

Well…..yes, but there are different definitions of design

analysis is problem focused, while design is solution focused. However, one morphs into another through the process. when model existing problem and model our new design of process.

a good analysis is important, so when to start? just before coding?

analysis start Right at the beginning ! When the project idea is first formed, some systems analysis activities are appropriate.

after first version formed, developer can continue throughout, depending on SDLC methodology, which will talk later

as mentioned before , developers should meet user’s need, somtimes they can not realised what they really want. To get fully understyand user’s idea developers Need to spend time with the users and observeand understand the current situation, systems and environment.

Modelling

OK, let’s explain former question, What is modelling. model is a way to define a analysised situation, which contain all data needed.

There are three layer of modelling,

Conceptual Analysis and Modelling is in high level

conceptual modelling sketches out broad concepts.

Logical analysis and modelling is more detailed and physical is much more based //todo

From requirement to analysis and modelling, we need a workflow to develop project. Let’s introduce Systems Development Life Cycle (SDLC)

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

we don’t need to understand pattrns here, we foucs on 4 phase

Required Gathering

The most critical step for SDLC. when trying develop a system. Good method of requirement gathering can prepared

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.