Agile vs waterfall
- 1. Traditional approaches of SDLC vs Agile methodology An informal presentation by Lohet Ramesh
- 2. Traditional SDLC • It is a stage gate model • Prescriptive and has a series of sequential steps • Documented properly i.e. emphasis is on initial requirements, contracts and plans • There is an audit trail resulting in user clarity • Costly because of its descriptive nature • Due to its prescriptive nature and a detailed initial plan, the resources need not be highly skilled • Since it is a stage gate model with costs separate for each stage a real-option can be taken to insure it • Popular types are the waterfall, v-model, spiral model etc.
- 3. Agile methodologies • A flexible model which is iterative i.e., a single requirement is iterated multiple times until the client is satisfied • Due to its constant interaction with clients, any change in their requirement is easily met by using the object oriented programming concept • Multiple iterations lead to very good quality of the end product leading to client satisfaction • Since it requires on-the-go thinking and as the requirements are not as comprehensively laid out as it is in the traditional model, the resources working on it should be highly skilled and should be adaptable to rapid changes • Modularity and Prototyping is its core feature as the client is shown the outline of how their end product would look in a short period and feedback is then taken from them to learn
- 4. Agile methodologies • Popular methodologies under agile are SCRUM, RAD(Rapid application development) and XP(extreme programming) • SCRUM is a management framework for incremental product development using one or more cross-functional, self- organizing teams of about seven people each. • It has three roles: Product owner, team and Scrum master • It provides a structure of roles, meetings, rules, and artifacts. Teams are responsible for creating and adapting their processes within this framework. • Scrum uses fixed-length iterations, called Sprints, which are typically 1-2 weeks long (never more than 30 days). Scrum teams attempt to build a potentially shippable (properly tested) product increment every iteration.
- 5. Agile vs Traditional approaches Agile Traditional • Ideal for smaller project ex: mobile application • Management is decentralised and distributed among the team members • Success of the project is measured by the business value delivered • Highly adaptable to changes • Minimal upfront planning • Return on investment is early in the product cycle • Size of the team is usually small, creative and highly talented • Refactoring is not costly • Chances of occurrence of risk is more which can impact the project • Ideal for large project ex: ERP systems • One person has all the control and other follow • Success of the project is measured by the conformation to the plan • Changes are not welcomed in the later stages of the project • Highly planned before the actual development starts • Return on investment is at the end of the project • Teams are large and do not expertise in their respective fields • Very costly to refactor code • Risks are identified, understood, prioritised and made sure it does not impact the project
- 6. Real-world examples of Agile • Boeing 787 is a real time example of Agile methodology being implemented as the specification document went from 2500 pages for Boeing 777 (787’s predecessor) to 20 pages for Boeing 787. • Multiple smaller teams are working independently on this aircraft which is similar to agile • This has caused a delay of 2+ years in the deployment of the aircraft which is a shortcoming of agile • Amazon e-commerce website data crawler • Another would be the department releases on a newly opened e-commerce website