Component Assembly Model

1.   Component based assembly model uses object oriented technologies. In object oriented technologies, the emphasis is on creation of classes. Classes are the entities which encapsulates data and algorithms.

2.   In component based architecture, classes (i.e. components required to build application) can be used as reusable components.

3.   Software development can be done using iterative approach.

4.   In CBD model, multiple classes can be used. These classes are basically the prepared components.

5.   The model works in following manner –

                I.      First identify all the required candidate components, i.e. classes with the help of application data and algorithms.

               II.      If these candidate components are used in previous software projects then they must be present in the library.

              III.      Such pre existing components can be extracted from the library and used for further development.

              IV.      But if the required component is not present in the library then build or create the component as per requirement.

               V.      Place this newly created component in the library. This makes one iteration of the system.

              VI.      Repeat step I to V for creating n iterations, where n denoted the number of iterations required to develop complete application.

Advantages of Component Assembly Model 

1.   This model emphasizes on reusability of software components. This reusability of component reduces the development cycle time by 70% and project cost by 84%. 

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Win-Win Spiral Model

 1.    The WIN-WIN model also suggests proper communication with customer. In reality customer and developers undergo through the process of negotiation. Successful negotiation occurs when both the sides win. This is called win-win result.

2.    Customer’s win means - Obtaining the system that satisfies most of the needs.

3.    Developer’s win means - Getting the work done with realistic and achievable budgets and deadlines.

4.    In WIN-WN spiral model negotiation activities are carried out at the beginning of each pass of the spiral.

5.    Various activities that can be carried out in WIN-WIN spiral model are

a.     Identification of ‘stakeholders’

b.    Determination of ‘stakeholders’ wins condition

c.     Negotiations of stakeholders striving for win condition. With the concerned software project team reconcile for win-win result. Then determine next level objectives, constraints and alternatives.

d.    Analyze and resolve the risks.

e.     Define next level of product and process.

f.      Validate process and product definitions.

g.    Take a review of product and give necessary comments on it.

6.    There are three anchor points that can be defined in WIN-WIN spiral model

a.     LCO – That means Life Cycle Objective. It defines the objectives for major software engineering activities.

b.    LCA – That means Life Cycle Architecture. It defines the software architectures that can be produced with all the objectives are set.

c.     IOC – That means Initial Operational Capability. It represents software with all the desired initial operational capabilities.

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Spiral Model

1.    This model possesses the iterative nature of prototyping model and controlled and systematic approaches of the linear sequential model.

2.    In this model, the software is developed in a series of increments.

3.    The spiral model is divided into a number of framework activities. These framework activities are denoted by task regions.

4.    Usually there are six tasks regions.

5.    Spiral model is realistic approach to development of large-scale systems and software. Because customer are developer better understand the problem statement at each evolutionary level. Also risks can be identified or rectified at each such level.

6.    In the initial pass, product specification is built and in subsequent passes around the spiral the prototype gets developed.

7.    During planning phase, the cost and schedule of software can be planned and adjusted based in feedback obtained from customer evaluation.

8.    In spiral model, project entry point axis is defined. This axis represents starting point for different types of projects.

9.    The task region can be described as-

i.      Customer communication – In this region it is suggested to establish customer communication.

ii.    Planning – All planning activities are carried out in order to define resources time line and other project related activities.

iii.   Risk analysis – The tasks required to calculate technical and management risks are carried out.

iv.    Engineering – In this task region, tasks required to build one or more representations of applications are carried out.

v.     Construct and release – All the necessary tasks required to construct, test, install the application are conducted.

vi.    Customer evaluation – Customer’s feedback is obtained and based on customer evaluation required tasks are performed and implemented at installation stage.

10.  In spiral model, the software engineering team moves around the spiral in a clockwise direction beginning at the core.

Advantages of spiral model

1.    Requirement changes can be made at every stage.

2.    Risks can be identified and rectified before they get problematic.

Disadvantages of spiral model

1.    It is based on customer communication. If the communication is not proper then the software product that gets developed will not be up to mark.

2.   It demands considerable risk assessment. If the risk assessment is done properly then only the successful product can be obtained.

 

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