System Analysis And Design

INTRODUCTION

Systems are created to solve problems. One can think of the systems approach as an organized way of dealing with a problem. In this dynamic world, The subject System Analysis and Design, mainly deals with the software development activities.

OBJECTIVES

After going through this lesson, you should be able to:
• understand a system
• understand the different phases of system developments life cycle
• know the components of system analysis
• know the components of system designing

Defining A System

A collection of components that work together to realize some objective forms a system. Basically there are three major components in every system, namely input, processing and output.




In a system the different components are connected with each other and they are interdependent. For example, Human body represents a complete natural system. We are also bound by many national systems such as political system, economic system, educational system and so forth. The objective of the system demand that some output is produced as a result of processing the suitable inputs.

SYSTEM LIFE CYCLE

System life cycle is an organisational process of developing and maintaining systems. It helps in establishing a system project plan, because it gives overall list of processes and sub-processes required developing a system.
System development life cycle means combination of various activities. In other words we can say that various activities put together are referred as system development life cycle. In the System Analysis and Design terminology, the system development life cycle means software development life cycle.
Following are the different phases of software development cycle:
• System study
• Feasibility study
• System analysis
• System design
• Coding
• Testing
• Implementation
• Maintenance

The different phases of software development life cycle is shown in Fig

Different phases of Software development Life Cycle

PHASES OF SYSTEM DEVELOPMENT LIFE CYCLE

Let us now describe the different phases and the related activities of system development life cycle in detail.

(a) System Study

System study is the first stage of system development life cycle. This gives a clear picture of what actually the physical system is? In practice, the system study is done in two phases. In the first phase, the preliminary survey of the system is done which helps in identifying the scope of the system. The second phase of the system study is more detailed and in-depth study in which the identification of user’s requirement and the limitations and problems of the present system are studied. After completing the system study, a system proposal is prepared by the System Analyst (who studies the system) and placed before the user. The proposed system contains the findings of the present system and recommendations to overcome the limitations and problems of the present system in the light of the user’s requirements.
To describe the system study phase more analytically, we would say that system study phase passes through the following steps:
• problem identification and project initiation
• background analysis
• inference or findings

(b) Feasibility Study

On the basis of result of the initial study, feasibility study takes place. The feasibility study is basically the test of the proposed system in the light of its workability, meeting user’s requirements, effective use of resources and .of course, the cost effectiveness. The main goal of feasibility study is not to solve the problem but to achieve the scope. In the process of feasibility study, the cost and benefits are estimated with greater accuracy.

(c) System Analysis

Assuming that a new system is to be developed, the next phase is system analysis. Analysis involved a detailed study of the current system, leading to specifications of a new system. Analysis is a detailed study of various operations performed by a system and their relationships within and outside the system. During analysis, data are collected on the available files, decision points and transactions handled by the present system. Interviews, on-site observation and questionnaire are the tools used for system analysis. Using the following steps it becomes easy to draw the exact boundary of the new system under consideration:

• Keeping in view the problems and new requirements
• Workout the pros and cons including new areas of the system

All procedures, requirements must be analysed and documented in the form of detailed data flow diagrams (DFDs), data dictionary, logical data structures and miniature specifications. System Analysis also includes sub-dividing of complex process involving the entire system, identification of data store and manual processes.

The main points to be discussed in system analysis are:

• Specification of what the new system is to accomplish based on the user requirements.
• Functional hierarchy showing the functions to be performed by the new system and their relationship with each other.
• Function network which are similar to function hierarchy but they highlight the those functions which are common to more than one procedure.
• List of attributes of the entities - these are the data items which need to be held about each entity (record)

(d) System Design

Based on the user requirements and the detailed analysis of a new system, the new system must be designed. This is the phase of system designing. It is a most crucial phase in the development of a system. Normally, the design proceeds in two stages :
• preliminary or general design
• Structure or detailed design

Preliminary or general design: In the preliminary or general design, the features of the new system are specified. The costs of implementing these features and the benefits to be derived are estimated. If the project is still considered to be feasible, we move to the detailed design stage.

Structure or Detailed design: In the detailed design stage, computer oriented work begins in earnest. At this stage, the design of the system becomes more structured. Structure design is a blue print of a computer system solution to a given problem having the same components and inter-relationship among the same components as the original problem. Input, output and processing specifications are drawn up in detail. In the design stage, the programming language and the platform in which the new system will run are also decided.
There are several tools and techniques used for designing. These tools and techniques are:
• Flowchart
• Data flow diagram (DFDs)
• Data dictionary
• Structured English
• Decision table
• Decision tree
Each of the above tools for designing will be discussed in detailed in the next lesson.

(e) Coding

After designing the new system, the whole system is required to be converted into computer understanding language. Coding the new system into computer programming language does this. It is an important stage where the defined procedure are transformed into control specifications by the help of a computer language. This is also called the programming phase in which the programmer converts the program specifications into computer instructions, which we refer as programs. The programs coordinate the data movements and control the entire process in a system.
It is generally felt that the programs must be modular in nature. This helps in fast development, maintenance and future change, if required.

(f) Testing

Before actually implementing the new system into operations, a test run of the system is done removing all the bugs, if any. It is an important phase of a successful system. After codifying the whole programs of the system, a test plan should be developed and run on a given set of test data. The output of the test run should match the expected results.
Using the test data following test run are carried out:

• Unit test

• System test

Unit test: When the programs have been coded and compiled and brought to working conditions, they must be individually tested with the prepared test data. Any undesirable happening must be noted and debugged (error corrections).

System Test: After carrying out the unit test for each of the programs of the system and when errors are removed, then system test is done. At this stage the test is done on actual data. The complete system is executed on the actual data. At each stage of the execution, the results or output of the system is analysed. During the result analysis, it may be found that the outputs are not matching the expected out of the system. In such case, the errors in the particular programs are identified and are fixed and further tested for the expected output.
When it is ensured that the system is running error-free, the users are called with their own actual data so that the system could be shown running as per their requirements.

(g) Implementation

After having the user acceptance of the new system developed, the implementation phase begins. Implementation is the stage of a project during which theory is turned into practice. During this phase, all the programs of the system are loaded onto the user's computer. After loading the system, training of the users starts. Main topics of such type of training are:
• How to execute the package
• How to enter the data
• How to process the data (processing details)
• How to take out the reports
After the users are trained about the computerised system, manual working has to shift from manual to computerised working. The following two strategies are followed for running the system:

i. Parallel run: In such run for a certain defined period, both the systems i.e. computerised and manual are executed in parallel. This strategy is helpful because of the following:
o Manual results can be compared with the results of the computerised system.
o Failure of the computerised system at the early stage, does not affect the working of the organisation, because the manual system continues to work, as it used to do.
i. Pilot run: In this type of run, the new system is installed in parts. Some part of the new system is installed first and executed successfully for considerable time period. When the results are found satisfactory then only other parts are implemented. This strategy builds the confidence and the errors are traced easily.

(h) Maintenance

Maintenance is necessary to eliminate errors in the system during its working life and to tune the system to any variations in its working environment. It has been seen that there are always some errors found in the system that must be noted and corrected. It also means the review of the system from time to time. The review of the system is done for:
• knowing the full capabilities of the system
• knowing the required changes or the additional requirements
• studying the performance
If a major change to a system is needed, a new project may have to be set up to carry out the change. The new project will then proceed through all the above life cycle phases.

Convert your ipad into laptop by using Clamcase

It's not even a month since the launch of iPad and its add on gadgets have started coming. A device called "ClamCase" manufactured by a company of the same name has launched this device which works as an iPad case, stand and keyboard add-on.

One only needs to place the iPad into the case and get started. From there, they can opt to keep it flat on the table or set it up in landscape view. The keyboard can be connected to the iPad via Bluetooth to give them the functionality of a laptop.

However it is a downfall that ClamCase, unlike most other laptops, won't be featuring a trackpad to help people navigate around the iPad screen. That means owners will still need to tap the display to get to where they want to go. The real function of the ClamCase, then, is to improve the typing experience and speed on the iPad and protect the tablet from damage.

ClamCase plans to launch its three-in-one add-on device in the fall. No word on the pricing yet.

Four Tricks to Get Ranking High on Search Engine

A common problem noticed among blogger is the futile attempt to get their ranking high on search engine. The solution to this problem is quite straightforward: Know what works and stick to it forever rather than deriving new methods everyday. Finding out what works, however, is another issue altogether. Therefore, I have decided to share what works for me. Here are four things that will help you to get your blog’s ranking high with search engines.

• Induce people to GOOGLE your brand
  Most of you wouldn’t agree with this method of improving your ranking. But, trust me, I have seen numerous examples proving my point.Let’s have a logical look on the point. Every search engine would want to help the page increase its ranking if people are readers are search for the brand keyword directly. Since Google and other search engines want to display best results on the initial pages, it will improve your ranking. So, here is the key. If you are launching a new product, marketing an existing product, or refereeing something, instead of linking it, use the brand name.

• Observe trade on Flippa.com
  At first, I thought not to discuss this idea with everyone as it reveals some remarkable link ideas, but I have vowed to deliver value to all my readers. So, here it goes. As you log on to Flippa.com, you will notice people are involved in buying and selling of top ranking sites. Having a closer look at all the top sites, you will notice that many business owners have managed to produce websites, get it to high ranking within a couple of months, and sell it for more than $5,000 quite frequently.Many sites with high ranking have nothing but spammy links. They have effectively managed to exploit these links. I wouldn’t, however, suggest you to use such link. But you can find some real good links that can help you get high ranking.
• Explore the power of GUEST POSTING
  People not using ‘guest posts’ to promote their sites, this is the most effective tip you will ever get to improve search ranking. Here is a precise and concise procedure to do it.

• Search for top blog in your niche, and check if they offer opportunities for guest posting. Even if they don’t, contact them.
• Looking for additional sources is easy. Google terms like “guest post” or “write for us”.
• If the site owner permits you for a guest post entry, write a remarkable article and send it in HTML text. This will make it easier for them to paste it and keep your links active.
• Don’t forget to insert non spammy link below your post. This will work to improve your ranking and attract enormous traffic.
• It’s a win-win situation. Site owner gets an excellent article, and you get traffic.

• ‘Unclean’ Bookmarking Links
  Though not a clean way to improve your ranking, it brings surprising results. Many social bookmarking links are helping many of my websites. You can target links on authority sites with specific anchor text. You can also paste links on new websites with quite uncompetitive areas or niches.

Save Tigers

What WWF-India is doing to save the tiger?

At the turn of the 20th century, according to sources, India had an estimated 40,000 tigers in the wild. In 2002, based on pug mark census, this number was 3,642. As per the monitoring exercise by Wildlife Institute of India in association with National Tiger Conservation Authority (NTCA), Government of India using camera traps, in 2008 we were left with only 1,411 tigers. This number is so small that they will be gone soon if we don’t wake up to the crisis.

WWF-India aims for a strategic and focused approach in its tiger conservation efforts. Our goal is to restore, maintain and protect tigers as well as their habitat and prey base in important tiger landscapes in India.

The objectives are to:

• Protect, restore corridors to ensure connectivity between tiger habitats while ensuring that human-tiger conflicts are reduced.
• Reduce pressures on the tiger habitats by promoting alternative livelihoods for local communities in and around tiger habitats.
• Create incentives for local communities as well as state and regional government and opinion-makers to support tiger conservation.
• Enhance capacities of the Forest Department to control poaching of tigers and prey species.
• Provide policy inputs at state and central levels to ensure effective measures for conservation of tigers and their habitats.
• Promote the political will as well as popular support within all sectors of society for tiger conservation.
  

• What you can do to save the tiger?

  The tiger is not just a charismatic species. It’s not just a wild animal living in some forest either. The tiger is a unique animal which plays a pivotal role in the health and diversity of an ecosystem. It is a top predator and is at the apex of the food chain and keeps the population of wild ungulates in check, thereby maintaining the balance between prey herbivores and the vegetation upon which they feed. Therefore the presence of tigers in the forest is an indicator of the well being of the ecosystem. The extinction of this top predator is an indication that its ecosystem is not sufficiently protected, and neither would it exist for long thereafter.
  
  If the tigers go extinct, the entire system would collapse. For e.g. when the Dodos went extinct in Mauritius, one species of Acacia tree stopped regenerating completely. So when a species goes extinct, it leaves behind a scar, which affects the entire ecosystem. Another reason why we need to save the tiger is that our forests are water catchment areas.
  
  When we protect one tiger, we protect about a 100 sq. km of area and thus save other species living in its habitat. Therefore, it’s not just about saving a beautiful animal. It is about making sure that we live a little longer as the forests are known to provide ecological services like clean air, water, pollination, temperature regulation etc. This way, our planet can still be home to our children.
  
  
  Spread the word: Go out loud and tell others that tigers are dying and that they need our help. You can form forums (or join existing ones) on the web for discussions and exchange views on tiger conservation. Reach school going children. WWF can help you in this regard.
  
  Be a responsible tourist: The wilderness is to be experienced and not to be disturbed and polluted. Follow the forest department guidelines when visiting any wilderness area, tiger reserve in particular. As the saying goes ‘Don’t leave thing anything behind except foot steps, and don’t take anything except memories.’
  
  Write to the policy makers: If you are really concerned and feel that more needs to be done for tiger conservation, then write polite letters to the decision makers - the Prime Minister, the Minister for Environment and Forests or even your local MP.
  
  Informing the nearest police station: If you know of any information on poaching or trade of illegal wildlife. You can also contact TRAFFIC- an organisation fighting the powerful poachers and pass on the information to them.
  
  Reducing pressure on natural resources: By reducing the use of products derived from forests, such as timber and paper.