Life cycle model
To Describes the steps followed by the project
team to produce a tangible software product that fully meets the requirements of the component or the part that the project set forth to build.
A set of activities, together with ordering
constraints among them, such that if the activities are performed properly and in accordance with the ordering constraints. The process that deals with the technical and management issues of software development is called SWP. Successful project talks about Cost, schedule and quality.
A set of activities that leads to the production of a
software product. There are many software processes, some fundamental activities are common to all software processes: Software Specification Software design and Implementation Software Validation Software evolution.
Product Engineering process(produce desired
product) Development process Project Management process Software Configuration Management Process Management process
ETVX Approach for process specification
A step in Development process
A software development process, also known as
a software development life cycle (SDLC), is a structure imposed on the development of a software product.
Linear Sequential Model Water – tight phases One phase is Completed before the next phase
Life cycle model
Waterfall model problems
Inflexible partitioning of the project into distinct stages
makes it difficult to respond to changing customer requirements. Therefore, this model is only appropriate when the requirements are well-understood and changes will be fairly limited during the design process. Few business systems have stable requirements. The waterfall model is mostly used for large systems engineering projects where a system is developed at several sites.
Limitations of Waterfall model
It assumes that the requirements of a system can
be frozen before the design begins. Freezing the requirements usually requires choosing the hardware(because it forms a part of the requirements specification). A large project might take a few years to complete. “Big bang approach” – an entire software is delivered in one shot at the end. It encourages “requirements bloating”. It is a document-driven process that requires formal documents at each phase.
• Attractive idea for complicated and large systems for
which there is no manual process or existing system to help determine the requirements.. • Based on Currently known requirements. • Customer can get actual feel of the system. Types: 1. Throwaway Prototype 2. Evolutionary Prototype
Horizontal Prototype A common term for a user interface prototype is
the horizontal prototype It provides a broad view of an entire system or subsystem, focusing on user interaction more than low-level system functionality, such as database access Vertical Prototype A vertical prototype is a more complete elaboration of a single subsystem or function.
Types of prototyping
Major types: first two.. Throwaway prototyping Evolutionary prototyping Incremental prototyping Extreme prototyping
Adv and Dis-Adv
Reduced time and costs: Improved and increased user involvement Disadvantages of prototyping Insufficient analysis User confusion of prototype and finished system Developer misunderstanding of user objectives Expense of implementing prototyping: Excessive development time of the prototype
Combines the features of waterfall model and
prototyping model. Rapid application development (RAD) is a software dev.methodology that uses minimal planning in...