1. Thinking about Information Systems -II
IT Projects from Conception to Delivery – SDLC
Project Management Approaches- Waterfall to Agile Methodology

2. Software Development Lifecycle (SDLC)
SDLC : A term used in systems engineering, information systems and software engineering to describe a process for planning, creating, testing, and deploying an information system
Describes the different stages involved in the project from the drawing board, through the completion of the project.
Requirement gathering and analysis
Design
Implementation/Coding
Testing
Deployment
Maintenance
Used during the software development process and are also called software development models
Each of these development models follows a life cycle to ensure the success of a software development process.

3. The User Designer Communication Gap
User Concerns
Designer Concerns
Will the system deliver the information I need for my work ?
How much disk space will the master file consume?
How quickly can I add the data ?
How many lines of product code will it take to perform this function ?
How easily can I retrieve the data ?
What is the most efficient way of storing the data ?
How much clerical support will I need to enter the data ?
What database management system should we use ?
How will the operation of my system fit into my daily business schedule ?
How to cut down on CPU time when we run the system ?

4. Stages in SDLC Preliminary analysis:
Find out the organization's objectives and the nature and scope of the problem under study.
Systems analysis, requirements definition:
It is the process of gathering and interpreting facts, diagnosing problems and recommending improvements to the system
Systems design:
Describes desired features and operations in detail, including screen layouts, business rules, process diagrams, pseudocode and other documentation
Development:
The real code is written here
Integration and testing:
Brings all the pieces together into a special testing environment, then checks for errors, bugs and interoperability
Acceptance, installation, deployment:
The final stage of initial development, where the software is put into production and runs actual business
Maintenance:
Phase that ensures system does not become obsolete. It involves continuous evaluation of the system in terms of its performance
Evaluation: This is where the system that was developed, as well as the entire process, is evaluated. Some of the questions that need to be answered include: does the newly implemented system meet the initial business requirements and objectives? Is the system reliable and fault-tolerant? Does the system function according to the approved functional requirements? In addition to evaluating the software that was released, it is important to assess the effectiveness of the development process. If there are any aspects of the entire process, or certain stages, that management is not satisfied with, this is the time to improve. Evaluation and assessment is a difficult issue. However, the company must reflect on the process and address weaknesses.

5. Benefits of Software Development Lifecycle
Improves the quality of a product by making it cost-efficient, effective and productivity
At the end of each stage a proper review is created that allows maximum management control
Helps in creating detailed system documentation called Software Requirement Specification (SRS)
SRS helps in assuring that system requirements can be traced back to specified needs of organization
The products can be reviewed to check whether they conform to user’s requirements of not.
Further changes can be made to suit the clients needs
Two popular ways to implement SDLC is using two types of SDLC – Waterfall and Agile
The main difference between these two models is that the waterfall model is a sequential process model and comes with a well detailed plan and requirements.
The agile model does not have strict guidelines like the waterfall model; adjustments can be made throughout the process.
Agile software development gives advantages that a waterfall model does not address.

6. Software Development Models
A framework that describes the activities performed at each stage of a software development project.
Comprise work practices, tools and techniques that are required to develop software.
Very efficient and enable software developers to build cost effective and reliable software to satisfy maximum number of customer requirements.
Software development models are used for organizing and creating documentation of the structure and flow of the data through a systematic process
Software development process has changed with the time by incorporating additional definitions, process models, structures and approaches to software development activity.

7. Waterfall Model
Each phase must be completed before moving to the next phase.
Used in small projects with no indeterminate requirements
After every phase a review is done to determine the accuracy of the product.
When to use the Waterfall Model :
Requirements are very well known
Product definition is stable
Technology is understood
New version of an existing product
Porting an existing product to a new platform.

8. Waterfall Model Strengths and Weaknesses
Easy to understand, easy to use
Schedules can be set with deadlines for each stage
Milestones are well understood
Good for management control (plan, staff, track)
Works well when quality is more important than cost or schedule
All requirements must be known upfront
Little opportunity for customer to preview the system
Difficult for customers to state all the requirements explicitly
Blunders / problems that are faced can’t be rectified until very late
Advantages :
Require business needs and requirements in beginning
Defines definite starting and ending points of a project
Early detection of errors
As all the stages are clearly defined so, this process ensures early detection of errors and misunderstanding in its each stage
Require Documentation , to support future enhancements in the project
Requirement specification document serve as the guideline for the development and testing phase
Each phase is discrete and team members involved in a stage ensures the perfection of the stage before delivering to next stage
This approach can be very efficient when team members are dispersed in different locations
The amount of resources required to implement waterfall model is lower than other methods
Disadvantages :
The greater disadvantage of this approach is that there is no way to go back. Once a stage is complete means it is locked
Sometimes it’s really tough to estimate time required for different phases and incorrect assumption can fail the project to meet its deadline
Waterfall model does not allow changes as per client’s requirement, so it is less flexible
If changes are to be made in waterfall process, the project has to be started all over again. This can be expensive for some organization.
Increase software development time and expense since client keep adding requirement on the list
Team members of rest of the phase sits idle except the team member who are under the current working phase.

9. Prototype Model
Waterfall model does not deliver a working model until a late stage. Therefore, you cannot detect any severe error at an early stage. The solution to this problem is to develop a working prototype with the available requirement details.
When to Use Prototyping Model ?
Requirements are unstable or have to be clarified
As the requirements clarification stage of a waterfall model
Develop user interfaces
Short-lived demonstrations
New, original development
With the analysis and design portions of object-oriented development.

10. Prototype Model Advantages Limitations
Improved , increased user involvement
Errors rectified at each stage
User confusion of prototype and finished system
Developer misunderstanding of user objectives
Expense and time of implementing prototyping
Advantages :
When prototype Model is shown to the user, he gets a proper clarity about his requirements. And feel the functionality of the software, so can suggest the changes and modifications.
When client is not confident about the developer’s capabilities, he asks for a small prototype to be built
It helps to demonstrate the concept to the investors to get funding for project.
It reduces risk of failure, as potential risks can be identified early and steps can be taken to remove that risk.
Constant interaction between development team and client provides a very good and co-operative environment during project.
Time required to complete the project after getting final SRS is reduces as the developers has a better idea about how he should approach the project
The customer does not need to wait long for working software
Feedbacks from customer are received periodically and the changes don’t come as a last minute surprise.
Disadvantages :
Sometimes the start-up cost of building the development team, focused on making prototype is high. And usually in starting Prototype is done at the cost of the developer. So it is done using minimal resources
It is a slow process
Once we get proper requirements from client after showing prototype model, it may be of no use
Too much involvement of client is not always preferred by the developer.
Too many changes can disturb the development team.
Customer could believe the prototype as the working version
Developer also could make the implementation compromises where he could make the quick fixes to the prototype and make is as a working version.
Often clients expect that a few minor changes to the prototype will more than suffice their needs
They fail to realise that no consideration was given to the overall quality of the software in the rush to develop the prototype

11. Iterative Model Design
Divide the requirements in various versions or build. In this model we follow multiple development life cycles such as multi-waterfall cycle. These cycles are divided into various smaller modules. During the first module, a working version of the software is produced.

12. Advantages Limitations
Iterative Model
Advantages
Limitations
Generates working software quickly and early
Easier to test and debug during a smaller iteration
Customer can respond to each build
Easier to manage risk
Needs good planning and design
Needs a clear and complete definition of the whole system before it can be broken down and built incrementally
Total cost is higher than waterfall
Advantages of the Iterative Model
The versions are provided after iteration of the incremental model.
After using first iterated model, user can give their suggestion and demand for changes
It is flexible to the customer’s requirements and easy to manage model
Better risk management is there in this model because one can confirm the outcome by the customer after every version because every version is prepared according to the plan
Easy to test as testing is done in iteration as per requirement
This model is used when requirements are clear to some extend but project scope requires pure linear approach
Complete implementation by decided dead line
Sometimes early increments can be implemented with fewer people.
Lover risk of project failure compared to other approaches.
Results are obtained early and periodically.
Parallel development can be planned.
Progress can be measured by setting milestone.
Testing and debugging during smaller iteration is easy
Limitations of the Iterative Model
Each phase of an iteration is very rigid and do not overlap each other.
Problems may arise related to system architecture because not all requirements are gather in initial stage of the development process
Each increment needs to be relatively small.
Mapping requirements to increments may not be easy so managing documents are very difficult.
Common features of the software are difficult to identify.
During development process changes are being done at first iteration. As if it continues to change and it never finished.
More resources may be required
More management attention is required due to frequent changes in requirements
Does not allow iterations within an increment.

13. Spiral Model
The spiral model can be described as the combination of linear sequential and iterative approach used for the software development process. In the spiral model, software development is done in a series of developed builds.
Advantages:
Spiral life cycle model is one of the most flexible SDLC models. Development phases can be determined by the project manager, according to the complexity of the project.
Project monitoring is very easy and effective as it is done in each phase of each iteration. This monitoring is done by experts or by concerned people. This makes the model more transparent.
Risk management is key feature of this model, which makes it more attractive compared to other models.
If changes are introduced at later stage in life cycle, coping with these changes isn’t a very big problem for the project manager
It is suitable for high risk projects, where business needs may be unstable.
A highly customized product can be developed using this model.
Since the prototype building is done in small fragments or bits, cost estimation becomes easy and the customer can gain control on administration of the new system
As the model continues towards final phase, the customer's expertise on new system grows, enabling smooth development of the product meeting client's needs
Disadvantages :
Cost involved in this model is usually very high
It is a complicated approach especially for the project with a clear SRS (System Requirement Specification)
Rules and protocols should be followed properly to effectively implement this model. Through-out the project life cycle development, it is very hard to follow rules and protocols
It is not suitable for low risk projects
Meeting budgetary and scheduling requirements is very tough with this software development process
Due to various customizations allowed from the client, it is very hard to use same prototype in other projects
It needs extensive skill in evaluating uncertainties or risks associated with the project and their abatement. 8. The models work best for large projects only, where the costs involved are much higher and system pre requisites involves higher level of complexity. 9. Risk assessment expertises are required. 10. Spiral may continue indefinitely.

15. Agile Software Development
Requirements and solutions evolve through the collaborative effort of self-organizing cross-functional teams
Advocates adaptive planning, evolutionary development, early delivery, and continuous improvement, and it encourages rapid and flexible response to change
Agile Methods
Extreme programming (XP)
Scrum
Crystal methodologies
Dynamic software development method (DSDM)
Feature-driven development
Lean software development

16. Scrum
Features are known as user stories as they are built from the end users perspective
Product Backlog :
Collection of the user stories / wish list of all the items that will make the product look great
Helps to decide which user stories one will add to the final product
Team Roles :
Product owner (sets the direction of the product , selects the right stories to go into the product)
Scrum Master/ Project Manager : the job continues smoothly, sets up meetings and monitors the work done
Developers, Testers, Customers, Executives,
Release Planning : identify the stories to be a part of the release backlog, estimates are needed here
Sprints short duration milestones that allow teams to tackle manageable amount of work
Helps to identify whether the project is going to be ready shipped
Burn down Charts : day by day check on how much work is left to be done
Advantages of Scrum
Agile scrum helps the company in saving time and money. 2) Scrum methodology enables projects where the business requirements documentation is hard to measure to be successfully developed. 3) Fast moving developments can be quickly coded and tested using this method, as a mistake can be easily rectified. 4) It is a lightly controlled method which insists on frequent updating of the progress in work through regular meetings. Thus there is clear visibility of the project development. 5) Like any other agile methodology, this is also iterative in nature. It requires continuous feedback from the user. 6) Due to short sprints and constant feedback, it becomes easier to cope with the changes. 7) Daily meetings make it possible to measure individual productivity. This leads to the improvement in the productivity of each of the team members. 8) Issues are identified well in advance through the daily meetings and hence can be resolved in speedily. 9) It is easier to deliver a quality product in a scheduled time. 10) Scrum can work with any technology/ programming language but is particularly useful for fast moving web technology or new media projects. 11) The overhead cost in terms of process and management is minimal thus leading to a quicker result.
Limitations of Scrum
Agile Scrum is one of the leading software development model because if there is not a definite end date, the project management stakeholders will be used to keep demanding new functionality to be delivered. 2) If a task is not well defined, estimating project costs and time will not be accurate. In such a case, the task can be spread over several sprints. 3) If the team members are not committed, the project will either never complete or fail. 4) It is good for small, fast moving projects as it works well only with small team. 5) This methodology needs experienced team members only. If the team consists of people who are new to this technology, the project cannot be completed in time. 6) Scrum works well when the Scrum Master trusts the team they are managing. If they practice too strict control over the team members, it can be extremely frustrating for them, leading to demoralisation and the failure of the project. 7) If any of the team members leave during a development it can have a huge inverse effect on the project development 8) Project quality management is hard to implement and measure if the test team are not able to conduct failure testing after each sprint

17. Extreme Programming - XP
For small-to-medium-sized teams developing software with vague or rapidly changing requirements
Coding is the key activity throughout a software project
Communication among teammates is done with code
Life cycle and behavior of complex objects defined in test cases – again in code

18. XP Practices (1-6)
Planning game – determine scope of the next release by combining business priorities and technical estimates
Small releases – put a simple system into production, then release new versions in very short cycle
Metaphor – all development is guided by a simple shared story of how the whole system works
Simple design – system is designed as simply as possible (extra complexity removed as soon as found)
Testing – programmers continuously write unit tests; customers write tests for features
Refactoring – programmers continuously restructure the system without changing its behavior to remove duplication and simplify

19. 40-hour week – work no more than 40 hours a week as a rule
XP Practices (7 – 12)
Pair-programming -- all production code is written with two programmers at one machine
Collective ownership – anyone can change any code anywhere in the system at any time.
Continuous integration – integrate and build the system many times a day – every time a task is completed.
40-hour week – work no more than 40 hours a week as a rule
On-site customer – a user is on the team and available full-time to answer questions
Coding standards – programmers write all code in accordance with rules emphasizing communication through the code
Advantages of XP
Constant feedback from customer Developer gets constant feedback from customer which helps them to add new features to the system being developed
Customers are available onsite Customers are constantly available on site. So, when developer team required asking anything it would be very easy
Pair programming gives better coding As programming is done in a team of two to three people, it would be beneficial to the coding. Because all the people in a team have different way of thinking relates to see a particular programming aspect. So better coding would be outcome of these aspects.
Refactoring is also beneficial Changes to the coding are admirable in XP. Instead of designing the entire system up front, design as you go, making improvements as needed. So the interface would not change.
Continuous Integration As new code is developed, it is tested and integrated with the old code. The entire code base is constantly being rebuilt, and retested in an automated fashion
Silly mistakes are quickly caught Simple mistakes such as syntax errors or repeated variable names can be easily caught and fixed right then and there.
Limitations of XP
) Skill disparity This is the number one potential problem. If the partners are of completely different skill levels, you might have one programmer doing all the work or constantly tutoring the other. This is ok if one wants to set up a teacher-student relationship or are introducing a new programmer to your system, but if not, it can defeat the entire purpose of XP.
2) Not actually getting the work done For some people pair programming sessions can easily generate in socializing sessions. There are some people who don’t work when there is someone next to them examining their work, these people will not benefit much either.
3) Developer egos This is something that is not likely to happen in a classroom setting, but in more experienced teams, each programmer might try to push their own ideas of how things should be done, both of which may be perfectly valid. These sorts of conflicts can be totally unsuccessful.
4) Could not release in time As members are working in teams, they might not be able to reach the target in time or complete the iteration in defined timebox. It might lead to late delivery of final product.
5) Required very good management If management is not done properly then it would be very tough to get work done form the all team members

20. Traditional development v/s agile development
Fundamental assumption
Systems are fully specifiable, predictable, and are built through meticulous and extensive planning
High-quality adaptive software is developed by small teams using the principles of continuous design improvement and testing based on rapid feedback and change
Management style
Command and control
Leadership and collaboration
Knowledge management
Explicit
Tacit
Communication
Formal
Informal
Development model
Life-cycle model (waterfall, spiral or some variation)
The evolutionary-delivery model
Desired organizational form/structure
Mechanistic (bureaucratic with high formalization), aimed at large organizations
Organic (flexible and participative encouraging cooperative social action), aimed at small and medium sized organizations
Quality control
Heavy planning and strict control. Late, heavy testing
Continuous control of requirements, design and solutions. Continuous testing
Compared to traditional software engineering, agile software development mainly targets complex systems and product development with dynamic, non-deterministic and non-linear characteristics, where accurate estimates, stable plans, and predictions are often hard to get in early stages—and big up-front designs and arrangements would probably cause a lot of waste, i.e., are not economically sound. These basic arguments and previous industry experiences, learned from years of successes and failures, have helped shape agile development's favor of adaptive, iterative and evolutionary development