Module 2.ppt

https://sites.google.com/a/cmrit.ac.in/manoj-c5559/ UNIT - 4 PROCESS OVERVIEW, SYSTEM CONCEPTION, DOMAIN ANALYSIS: Process Overview: Development stages; Development life cycle. System Conception: Devising a system concept; Elaborating a concept; Preparing a problem statement. Domain Analysis: Ov...

https://sites.google.com/a/cmrit.ac.in/manoj-c5559/ UNIT - 4 PROCESS OVERVIEW, SYSTEM CONCEPTION, DOMAIN ANALYSIS: Process Overview: Development stages; Development life cycle. System Conception: Devising a system concept; Elaborating a concept; Preparing a problem statement. Domain Analysis: Overview of analysis; Domain class model; Domain state model; Domain interaction model; Iterating the analysis. Development Stages System Conception Conceive an application and formulate tentative requirements Analysis Deeply understand the requirements by constructing models To specify what must be done. Domain analysis focuses on real-world things whose semantics the application captures. Application analysis addresses the computer aspects of the application that are visible to users  Development Stage System design Devise the architecture, Devise a high-level strategy — the architecture — for solving the application problem. The choice of architecture is based on the requirements as well as past experience. Class design Determine the algorithms for realizing the operations,To emphasis from application concepts toward computer concepts. To choose algorithms to implement major system functions. Implementation Translate the design into programming code and database structures Development Stages Testing Ensure that the application is suitable for actual use and actually satisfies requirements Training Help users master the new application Maintenance Preserve the long term viability of the application Development Life Cycle Waterfall Development Iterative Development Where to use the waterfall model  Requirements are very well known.  Product definition is stable.  Technology is understood.  New version of an existing product. Waterfall model Diagram Requirement In this phase business analyst will collect the requirements with an interaction of client and Gathering collected requirements will be documented. In this phase system analyst will study the client Requirement requirements and prepare the system requirement Analysis specification. In this phase design architecture is the responsible to decide architecture of an application in order to full- Design fill the client requirements. In this phase developers will write the program using Coding programming languages or scripting languages in order to develop the application. Initially developers will perform unit testing and integration testing using of white box testing, After Testing that separate team will be perform system testing using black box testing Release After the testing client satisfied on work product then we deliver application to the customer to use at live & environment. While using this application client Maintenance identify can some defects in existing s/m then he will send to the CR to CCB.  ADVANTAGES  A waterfall model is easy to implementation.  It helps to find errors earlier  Easy to understand, easy to use.  Works well when quality is more important than cost or schedule  Documentation is produced at every stage of a waterfall model allowing people to understand what has been done..  Disadvantages  It is only suitable for the small size projects.  Constant testing of the design is needed.  If requirements may change the Waterfall model may not work.  Difficult to estimate time and cost for each stage of the development process.  Adjust scope during the life cycle can kill a project.  High amount of risk and uncertainty.  This model is not suitable to handle dynamic changes in the requirements Iterative Development First develop the nucleus of a system, then grow the scope of the system… There are multiple iterations as the system evolves to the final deliverable. Each iteration includes a full complement of stages: analysis, design, implementation, and testing Devising a System Concept New functionality Streamlining Simplification automate manual process  Integration Analogies Globalization Elaborating a Concept Good system concept must answer the following questions  Who is the application for? Stakeholders of the system  What problems will it solve? Features  Where will it be used? Compliment the existing base, locally, distributed, customer base  When is it needed? Feasible time, required time  Why is it needed? Business case  How will it work? Brainstorm the feasibility of the problem The ATM Case Study Develop software so that customers can access a bank’s computers and carry out their own financial transactions without the mediation of a bank employee. The ATM Case Study Who is the application for? We are vendor building the software  What problems will it solve? Serve both bank and user  Where will it be used? Locations throughout the world When is it needed? Revenue  Why is it needed? Economic incentive. We have to demonstrate the techniques in the book  How will it work N-tier architecture, 3-tier architecture Preparing a problem statement Design the software to support a computerized banking network including both human cashiers and automatic teller machines (ATMs)to be shared by a consortium of banks. Each bank provides its own computer to maintain own accounts and process transactions against them. Cashier stations are owned by individual banks and communicate directly with their own bank’s computers. Human cashiers enter account and transaction data......