Delivery in day(s): 5
Level 4 Computing & System Development
Unit Number and Title
Unit 9 System Analysis and Design
What is SDLC?
System Development Life Cycle (SDLC) is a process which an application or software product goes through during its life span.
Phases of SDLC can be divided into 5 phases:
Requirement Analysis – This is the initial step in project development. All the requirements as discussed from end users are gathered and system / software requirement specification document is formed.
Design – In this phase actual structure of project is designed. The hardware and software requirements are chalked out and a software / system design specification document is formed.
Implementation or Coding – This is the major and longest step in project development. The actual coding starts in this phase, as per the requirements and design phase.
Testing - After the coding gets completed, software is tested for any discrepancies. This phase goes through numerous steps like black box (functional + non-functional) testing and white box testing etc.
Maintenance – This is the last and final phase which can extend depending upon the project requirement
There are various approaches / models to system development life cycle (SDLC).I`m going to explain the following models:
Waterfall, V-Shaped, Prototyping, RAD, spiral and incremental model
Figure: Stages of Waterfall Model
Advantage – As output of previous phase acts as input of next phase, therefore each phase is completed before the next phase begins, so there is no overlapping of phases. Simple to implement, no time consuming. It works well for smaller projects where requirements are very well understood.
Disadvantage – One of major drawback with this approach is that once we are in testing phase it is difficult to go back in previous phase and change some requirement which was not well understood. Hence, this approach is full of risk and we have to wait for working software till the end of life cycle. Not suitable for the projects where requirements are at a moderate to high risk of changing and as well, not good model for complex and object-oriented projects.
Business Requirement Specification -> Acceptance Testing
System requirement specification -> System Testing
High Level Design -> System Integration Testing
Low Level Design -> Component Testing
Coding -> Unit Testing
Figure: Stages of V-Mdel
Advantages – Preliminary testing activities like test planning and test designing happens before coding, thus lot of time and cost are saved as chances of error become less. It avoids the downward flow of the issues and it works for small projects where requirements are easily understood
Disadvantage– As software is developed in coding phase so if any modifications are there then requirement and design specs need to be updated.The model is very rigid and not flexible and does not handle iterations or phases. It works only for small or medium projects.
Figure: Spiral Model
Advantage – This approach is appropriate for mission critical and risk based projects.
Disadvantage – Very expensive and cannot be applied to small projects.
Advantage – Customer satisfaction is high as he gets to see the product functionality with each release.
Disadvantage – We cannot assess the effort required to build the project in beginning.
I found Incremental model to be best suitable for managing public library of British Computer Center.
According to this approach, the project is built in rapid incremental cycles. There are many functions and checks in a library like:
Now we can divide this entire library management into small sections or modules or target to be achieved, following the agile model approach. At a time one functionality can be covered up with each build, like incorporating the data of suppliers, incorporating the check that not more than 3 books can be issued at a time etc. With each release user gets to see am overall improved system with new functionality. User can visualize the progress of the system at every interval.
The incremental model meets the requirements of British computer center – Library management system adequately.
Feasibility study is the analysis of the project on three criteria:
This means that is the project that we are going to handle can be developed by the proposed technology or not.
This means, is the proposed solution within our budget or cannot be developed within prescribed budget.
Is the project that we are going to make reap us benefits or it is not of any use.
Advantages and importance –
In our project of British Computer Center – Library management system, we need to determine the input variables like cost, time and efforts required to automate the system.
All the transactions were being recorded in files, now they will have to be entered into the software so that the entire system can be managed easily. It will save lot of time of borrowers and library staff as time required to search a book will be reduced, issuing of books, return of books, checking the constraints like whether the person has already borrowed books before or is he attempting to borrow more than three books will be checked.
British Computer Centre – Library Management System can be built within the prescribed budget It is a small but very effective project which will handle multiple tasks simultaneously and reduce human effort, time and cost.
Yes, British Computer Centre – Library Management System is a cost effective and reasonable project. A meaningful project has been created in small budget.
Yes, this project will automate the entire library system and will save lot of time, cost and effort of librarian.
There was a need to automate the public library of British Computer Center as members of BCC are increasing day by day and every transaction has been done manually. It was very difficult to check the availability of books, keeping track of the borrowers, maintaining record of fine etc, therefore by making a computerized system all these issues can be sorted instantaneously.
All the necessities of this system are well thought and as per the suggestions of library staff. The hardware and software requirements of the system have been jotted down, and efforts have been made to make this project cost effective.
In this project, our major pre-requisite was to automate the BCC library system to handle the tasks conveniently and cost effectively. Feasibility study helped a lot in finding out the financial and technical requirements of the system.
By implementing feasibility analysis, we have been able to build effective system within short time span and within limited budget.
Here I am defining a template to capture business requirements and specification for developing the automated BCC library system, containing points which are needed to be covered in feasibility study-
Business requirements, user requirements, functional requirements, usability requirements, performance requirements (Availability, responsiveness, reliability, capacity, scalability, disaster recovery), security requirements (user security, data security), legal compliance requirements (privacy and funding) etc.
Q1 –Do you think the existing system can be automated?
Answer –Yes, the existing system must be automated to track the day to day transactions easily.
Q2 –What can be the prospective modules within the system?
Answer – Login, sign up, pay fine, issue books, search books, reserved text books.
Q3 – Can a person get more than 3 books issued at a time?
Answer – No a person cannot issue more than three books at time. He has to return one of the books to get new book issued.
Q4 –Can a person get reserved text books issued?
Answer – No a person cannot get reserved text books issued.
Q5 – When does a person has to pay the fine?
Answer –If a person, keeps the book for more than 3 weeks then he has to pay fine.
Q6-Can there be multiple copies of same book?
Answer – Yes, there can be multiple copies of same book in library.
During requirement analysis and feasibility study and after the interview with employees from the library I found following scenarios:
In the above use case diagram, there are two actors – Borrower and librarian.
The borrowers gets registered into the system, signs in, enters personal details, check book availability, gets book issued, returns book.
The librarian issues the book, accepts fine and maintains account of membership fee and fine.
Figure – Activity Diagram for BCC library system
The main requirement of British Computer Center was to automate its library system as new members were joining day by day and it was difficult to manage all activities like keeping track of new members, searching books, issuing books, managing account for membership fee and fines, managing suppliers etc, manually.
After automating all processes of library system, people who want to become members of the system can follow these steps:
These entire criterions are getting fulfilled with new library system and the BCC business requirements are met.
In traditional library system, every transaction has to be recorded in files and maintaining those file was a big issue. After automating it, we can keep away with the files and every transaction can be recorded in computers, thus it saves lot of time in searching and also saves lot of energy of the librarian as well as the person who wants book.
The main functions of a public library are searching books, issue and return of books and paying fines, adding new members and updating existing members. All these functions were functional in old library management system. In our British Computer Centre, we have tried to automate all these functions so that we can save upon effort, cost and time.
At present the automated library system is satisfying the basic functionality of a public library. We can enhance the scope of this arrangement in future by giving complete control to the user and slaying the need of a librarian. A registered user will login into the system, search for the book and check for its availability, if sufficient copies are available + he is clear from any fine for non submission on time or he has borrowed less than 3 books at a time, then system will allow him to get the book issued. The person can take the book from the library shelf and scan the bar code at time of exit from library. No one can carry the books from library without getting them issued. Reserved text books cannot be issued, they can just be read in library. This is an idea for enhancing the scope of this system in future.
We have to design a Library Management System for BCC / British Computer Centre. Within the prescribed budget and allocated time we have to divide our set of activities to be completed. Currently all the activities are manual but the goal of BCC is to automate its library.
We know how data flows between various entities within the system. In task 3 above I sketched the activity and use case diagram of the system, based on that we can plan the action taken to achieve the goal.
We can divide the system into following modules:
Based on these module and integration within these, an automated system can be built which will micromanage these activities and help users in conveniently performing their activities.
Waterfall model [Online]. [Accessed on 20 December 2014]. Available on world wide web: <http://istqbexamcertification.com/what-is-waterfall-model-advantages-disadvantages-and-when-to-use-it/>
V Model[Online]. [Accessed on 20 December 2014]. Available on world wide web: <http://istqbexamcertification.com/what-is-v-model-advantages-disadvantages-and-when-to-use-it/>
RAD model [Online]. [Accessed on 20 December 2014]. Available on world wide web: <http://istqbexamcertification.com/what-is-rad-model-advantages-disadvantages-and-when-to-use-it/>
Incremental model [Online]. [Accessed on 20 December 2014]. Available on world wide web:<http://istqbexamcertification.com/what-is-agile-model-advantages-disadvantages-and-when-to-use-it/>
Feasibility study [Online]. [Accessed on 20 December 2014]. Available on world wide web: <http://www.businessdictionary.com/definition/feasibility-study.html>
Feasibility study [Online]. [Accessed on 20 December 2014]. Available on world wide web: <http://www.referenceforbusiness.com/small/Eq-Inc/Feasibility-Study.html>