The latest ‘Site Reference’ newsletter has been released. The featured article is titled “Software Development Life Cycle Models” by P.Lobrin. [Site Reference Newsletter]


The latest Site Reference newsletter has been released.

‘Software Development Life Cycle Models

by P.Lobrin

Before, whenever a developer is tasked to perform programming or coding, he immediately would jump to it, start programming with or without full knowledge of what the system would look like, how the features are arranged, etc. It is probably okay only if you’re just building a very simple system. However, if you’re building a complex and sophisticated system, it will take a long time for you to finish. Worse, you start to suffer from “groping in the dark” syndrome since your full of ideas, you want to implement them all, but you tend to forget about them because other features need to be prioritized.

That was before. Now, whether an IT system is small, medium or large scale, it is important to have a proper software/system development plan from beginning to end. It saves time, features of the system are well documented and will not be forgotten regardless of priority, and above all, there is proper management and execution of plans.

System Development Life Cycle (SDLC) models help in the complete development of a system, right from the conceptual stage to the customer delivery stage. SDLC is very useful if one has a complicated system to build. SDLC is the overall process of developing information systems through a multi-step process, from investigation of initial requirements to analysis, design, implementation and maintenance.

To properly illustrate the SDLC models, I shall present them in bullet form

1. Waterfall Model
“¢ One of the older SDLC models
“¢ Each single step in the process of system development is first written down in the form of specifications and reports. Only then are the actual phases initiated in practice
“¢ The execution of a project appears as a sequence of stages in which the output of each stage becomes the input for the next
“¢ The stages in Waterfall method are divided into the ff:

1. Project planning / feasibility study ““ commonly known as Requirements Stage. It is in this stage that developers/stakeholders determine the project goal
2. System analysis ““ refines project goals into defined functions and operations. It also analyses end-user information needs (Specification stage)
3. System design ““ describes desired features and operations in detail (Design stage)
4. Implementation / Coding (Implementation stage)
5. Integration and testing ““ brings all the individual system components into one, then testing it for errors, bugs, etc. (Integration stage)
6. Acceptance, Installation, Deployment ““ final stage of development where the software is put into production
7. Maintenance ““ this goes on apparently forever since changes, additions, etc are always essential, important and needed in a software application especially in the area that involves business and monetary transactions.
“¢ Drawbacks
1. Works well on simplistic activities
2. Assumes that the only role of users is in specifying requirements and that all requirements can be specified in advance. Unfortunately, requirements grow and change
3. It is, thus, well suited to projects that has low risk in the areas of user interface and performance

2. Spiral Model

“¢ Most generic of the models. Most life cycle models can be derived as special cases of the spiral model
“¢ Set of important requirements are selected for each prototype. Thus, developers can split the requirements and work first on those with high priority
“¢ Employs a risk management approach to software development especially in the stages of Specification, Design, Implementation and Integration
“¢ Emphasizes the need to reiterate earlier stages a number of time as the project progresses
“¢ Actually a series of short waterfall cycles, each producing an early prototype, representing a part of the entire project. It’s like using the waterfall model as guide in doing one prototype only.
“¢ If one prototype is finished (except perhaps the polishing of graphics), a developer can proceed to the next prototype. Build, test and integrate to the first prototype
“¢ Helps demonstrate a proof of concept early in the cycle
“¢ Incorporates prototyping and software quality objectives
“¢ Gives early focus to reusable software
“¢ Accommodates life cycle evolution, growth and requirement changes
“¢ Focus on early detection and design (architecture) flaws
“¢ Useful in hardware-software projects

3. Build and Fix Model

“¢ Crudest of the models
“¢ Implementation of system without specification nor design
“¢ May work for small scale projects
“¢ Code is written, then modified until client is happy
“¢ VERY RISKY!
“¢ I know of a developer who does just this kind of work strategy. He was given an assignment, but instead of planning properly, he will just code it immediately without specification or design. He improves it until his client is happy. If the client is dissatisfied, he doesn’t give a damn about it.

4. Rapid Prototyping Model

“¢ Emphasis is on creating a prototype that looks and acts like the desired product in order to test its usefulness
“¢ Develop a system with reduced capability
“¢ Present to client for approval
“¢ Once the prototype is approved, it is discarded and the “real” software is written.
“¢ Develops specification with better understanding
“¢ Exactly like the Spiral Model, where a prototype or only “shadow” of the real software is made, where the system (during implementation stage) is not that graphically perfect but features are functioning well for testing purposes
“¢ Only difference is, in Rapid Prototyping, it requires client approval prior to the building of the “real” software

5. Incremental Model

“¢ Divides the product into builds, where sections of the project are created and tested separately
“¢ Each build contains an operational quality subsystem
“¢ Each additional build, a new subsystem is integrated with the previous build
“¢ You will notice that this model is very much like the Spiral Model except that instead of prototype, they’d rather call it builds. These builds, like prototypes, are tested separately first. Each build has a subsystem in Incremental Method, whereas in Spiral, subsystems may or may not be used
“¢ Likely to find errors in user requirements quickly

6. Synchronize and Stabilize Model

“¢ Type of Incremental Model
“¢ Allows many teams to work efficiently in parallel
“¢ A nightly compilation of builds of the entire project is made to piece together all current components
“¢ An alpha release was done for internal testing, a couple of beta releases took care of a wider testing range outside the company. Finally, a release candidate leading to the final version, called a gold master, was released to manufacturing
“¢ At some point before each release, specifications would be frozen and the remaining time spent on fixing bugs
“¢ There is heavy emphasis in schedule management and perfection

7. Fountain Model

“¢ Support Incremental Development
“¢ Recognizes that some activities can’t stand before others, yet there’s a considerable overlap of activities throughout the development cycle
“¢ Implies that you do some analysis, then some design, then some implementation
“¢ Parallelism among various phases and iteration within phases
“¢ Development of an object-oriented system that more likely to lead us to focus on sections of the whole known as clusters or subsystems
“¢ Subsystems are collections of classes which work closely together
“¢ Supports human learning and is recommended for most projects

SDLC is a systems approach to problem solving and is made up of several phases. A developer may or may not use or apply SDLC, but based on my experience, it is highly advantageous to use one. We did a system before where we didn’t plan much how we will execute, start and finish building a system. The result was a complete catastrophe! We suffered “groping in the dark” syndrome, regretted ever working with one another, and suffered too many expenses and too much time delay. Learning from the lesson, it is, thus, highly recommended to properly plan the flow of activities in building a system through SDLC as one of the tools in management.

About The Author

A person dedicated to IT project management and software development. http://bonifaciosd.blogspot.com/

Top Strategies and Intelligence…

Foundational Link Building Part II- Article Marketing

Last week we talked about building links through directories. Now we turn our attention to article marketing which is about more than just mere links. At least this is the mind set one needs when approaching it. You see, ultimately one must go beyond links. Think about the actual value of the placement as far as potential traffic, branding and reach. You will find that when you do so, that the links are of better quality and the benefits greater. As we learned last week once again quality supersedes quantity.

Website Terms of Use: Are Yours Enforceable? Does It Matter?

Your website’s Terms of Use govern all visitors to your site — both casual visitors and registered customers. Terms of Use are typically referred to as “browser-wrapped” agreements because there is no requirement to click an I AGREE button. So, the question I’m often asked is… since the Terms of Use do not require a click, are they legally enforceable? And if not, why have them on the site?

SEO Elite v4- The Brutally Effective SEO Software

The granddaddy of all SEO tools is back with version 4. So if you’re sick of been kicked around by the search engines, now’s the time to fight back…
Get the latest strategies instantly or share them with your own visitors with Site-Reference’s RSS Feeds.

A Few Words From Our Experts…

Guarantees That Knock Customers off the Fence

Put yourself in your clients shoes. No, strike that. Put yourself in your prospects shoes (a prospect being someone youve never marketed, sold to or married before). She doesnt know you; she doesnt trust you, and she couldnt care less if you drop dead tomorrow. But, through deft marketing-youve captured her attention! Her eyeballs are yours! How does it happen…

Succeed With These Webmaster Resources…

Google Apps Tour Video

Take a quick tour of Google Apps to learn how your organization can benefit from Google’s innovative tools.

Get “Website Magazine” Delivered to Your Door Free!

Until now, there has not been a magazine that caters exclusively to the business of running a website. Website Magazine has tapped premier talent in the Internet industry for our content and each and every issue will contain practical advice and insights for website owners.

Four Ways to Supercharge Your Small Business’ Online Presence

Free white paper: Small Business Owners need more than an online presence to gain a competitive edge in the marketplace, they need Web capabilities that allow them to boost their business and bottom line. By developing robust online capabilities for their businesses, not only do they have a better chance of standing out among the crowd, they also are better-equipped to compete with midsized and large businesses and their dedicated IT staffs.

Questions, Answers and Discussions From Our Members…

Google Tests Description Snippet Length

The latest from Google- they are testing they are allowing users to customize their search results based on the length of the descriptions that accompany each result. Here’s how it works…

Server Serving Duplicate Pages

I’m currently developing an SEO strategy for of our site and wonder what benefits we will get from paid submissions? We currenlty have some links from related sites and these are growing. Are paid submissions worth the price?

Paid Submissions

While Google Analytics is a powerful program, there is only so much information about our sites that we want to share with Google. An appealing newcomer in the Analytics class is Woopra; feature rich and free- a combo we love. Before we go crazy over it, we want to hear of other people’s experiences with Woopra. Have you tried it?

Cooking With Balls

Several members have been interested in our affiliate program, or setting one up of their own. But how exactly does an affiliate program work and what are the benefits to both parties. Find out here…

Newsletter Information

RSS Feed: Use our articles as your content – subscribe to our RSS feed

Want to read more articles? Go to the front page of Site Reference

We also have plenty of articles in our archives

*IMNewswatch would like to thank Site-Reference for granting permission to reprint the latest newsletter.

Sharing is caring