introducing systems analysis design development

IntroducingSystems Analysis, Design &

Development Concepts

Shafiul Azam Chowdhury

Task: Build a Simplest Accounting S/W

• You’ve been offered to build a very basic accounting software for Bangoo Banks Inc.– You’ll need to collaborate with 3-4 other

developers.– You’ll receive handsome amount of cash for full

functional software!– Deadline: very, very strict. Say, couple of months?

What are you going to do?

• Divide the total project in visible sections, say: – User Accounts– Human Resource– Accounting– Etc…

• And started asking questions to your clients how they want the program behave, design database…

All four developers started coding as fast as you can to maintain deadline.

After some days… you felt like integrating your works?

• But you figured out you need a change in some part, you could change it, but others’ code can break?

• You hardly understand what your friend means by variable baln or function register()

• Your disc crashed and your codes are gone? • You’ve created too many folders like code_old

code_working, code_new2, code_final… now what?• How do you merge everybody’s code to a full-

functional system?

Messed Up?

• Without putting your code in a function, you just wrote it down, thinking, “Hey, I’ll not use this code anywhere else! So Why do I need to put it in a function or class?”

• But, you never know…– Client may change his mind– New functionalities may appear in future– And you’re very likely to duplicate same codes.– Man is mortal. To fix buggy codes you’ll need to investigate

your whole project number of times you copy-pasted same code. • Hard to find bugs.

Software Evolves…

• If your software is usable, it will have changes in it and have future releases.

• Clients will add new features, or users will want changes.

After some days, you’re about to bring some changes in your code.

And…Is that

Hebrew?

You don’t understand your

own code

If you don’t practice standards, it’ll be very, very difficult to maintain the project later.

So What are best practices?

Software Development Life Cycle

Introducing SADD

• Systems…– Step 1: Analysis– Step 2: Design– Step 3: Development

• Step 4: Evolve! Back to step 1

First Step: Systems Analysis

• Known as Requirement Analysis• Extract information from your clients on what

the software is supposed to do.• Place them on SRS Cards

• Useful to understand the total scope of application, defining priority and leads to modular design.

Sample Requirement Analysis for some Alumni Website…

SRS (Software Requirement Specification) Cards for Requirement Analysis

Step 2: Design your system

• Once you’re done with analysis, design it.• The great majority of the types of errors found

in testing the code had originated in the design phase – See figure in next slide.

Systems Design

• Following Design Patterns– Why reinvent the wheel?

• Modular Design– Loosely coupled code– Easy to extend your program– Code less. Reuse your code

• Build Wireframes• Follow Single Responsibility Principle

Building Wireframe

• Create Mock-up/prototype of your application before starting coding.– Can be built using GUI tools very rapidly– Client can know how your application will look

like/interact with users.– Non functional.

Wireframe Tools

Single Responsibility Principle

Development: Teamwork

Code Green. Test Units.

Documentation

• You alone are not coding– Others will work with your code– You will work with other’s code.

• Provide Documentation

Take help of Development Tools

• You figured out you need a change in some part, you could change it, but others’ code can break?

• You hardly understand what your friend means by variable baln or function register()

• Your disc crashed and your codes are gone? • You’ve created too many folders like code_old

code_working, code_new2, code_final… now what?

• How do you merge everybody’s code to a full-functional system?

Refractor

Distributed

Repos

Revision

Controlling

Unit Test

Understanding Your Responsibility

Is that you?

You need to work with a

lot of people!

Project Management Tools

• Coding is not your only responsibility.– Issues are assigned to you by your Project

Manager– Bug fixing tasks assigned to you– You fix code and re-assign it to Tester.

• To simplify all these, various Tools are available. – Using these tools guarantee standards.

Tools: Revision Controlling

• Git is a powerful distributed version controlling system.– Stores complete history of your source code at

different stages of project life cycle.– Easy merging of everyone’s copy of work.– Distributed.

Project Management Tools

• Project Management applications come with rich features like– Role Management (PM, Tester, Designer,

Programmer,…)– Bugs Reporting– Issue Tracking & Assigning– Gaunt Charts for schedule management– Documentation

Tools: Gaunt Chart

Thank You!

• Presentation prepared by– Shafiul Azam Chowdhury– Student, CSE, BUET– http://shafiul.users.sf.net

References• http://mixergy.com/wp-content/uploads/fast-typing.jpg• http://www.confessionsofaphotoshopnerd.com/storage/Confessions%20of%20

a%20photoshop%20nerd.jpg?__SQUARESPACE_CACHEVERSION=1294205000507

• http://www.fgsd.com.au/wp-content/uploads/2011/09/Software-Policies-Processes.jpg

• http://en.wikipedia.org/wiki/Systems_development_life-cycle• http://sunset.usc.edu/csse/TECHRPTS/1975/usccse75-501/usccse75-501.pdf• http://farm6.static.flickr.com/5227/5643033953_9b542af5a1.jpg• www.jsu.edu/mcis/docs/SRSSample.doc• http://cdn.seomoz.org/images/upload/axure-wireframe.gif• http://www.re-vision.com/webwork/p27wireframes/drawing_small.jpg• http://elegantcode.com/2008/12/22/single-responsibility-principle/• http://www.emqube.com/images/side_team.jpg• http://www.bluecollarobjects.com/pub/Main/TestDrivenDevelopment/RedGren

RefactorTight.jpg• http://www.agilemodeling.com/images/generalizingSpecialistsTaylorism.jpg• http://home.snc.edu/eliotelfner/333/pictures/Gantt.gif