Agile came about as a “solution” to the disadvantages of the waterfall methodology. Instead of a sequential design process, the Agile methodology follows an incremental approach. Developers start off with a simplistic project design, and then begin to work on small modules. The work on these modules is done in weekly or monthly sprints, and at the end of each sprint, project priorities are evaluated and tests are run.
- Agile methodologies (e.g. Scrum, XP, Kanban, Crystal etc) are often more difficult to understand than linear, sequential ones – at least initially.
- In waterfall Solution designers often aren’t able to foresee problems that will arise out of the implementation of their designs.
Since this was written the Waterfall Approach has had several key changes and adaptations incorporating agile methodology into the stable and higher business-plan relating system.
Both Agile and Waterfall methodologies have their strengths and weaknesses. The key to deciding comes down to the context of the project.
Is it going to be changing rapidly? If so, choose Agile.
Do you know exactly what you need? Good. Then maybe waterfall is the better option.
Or better yet?
Consider taking aspects of both methodologies and combining them in order to make the best possible software development process for your project.
Having said all that, there are still circumstances in which the waterfall method can be suitable – for example, where requirements are guaranteed to be unchanging and there is very little uncertainty or if the project if very simple – but those circumstances are becoming fewer and farther between.Both Agile and Waterfall methodologies have their strengths and weaknesses. The key to deciding comes down to the context of the project.
Is it going to be changing rapidly? If so, choose Agile.
Do you know exactly what you need? Good. Then maybe waterfall is the better option.
Or better yet?
Consider taking aspects of both methodologies and combining them in order to make the best possible software development process for your project.
Values from the Agile Manifesto
- Individuals and interactions over processes and tools
- Working software over comprehensive documentation
- Customer collaboration over contract negotiation
- Responding to change over following a plan
- That is, while there is value in the items on the right, we value the items on the left more.”
Ever since 2001, the use of methods supporting these values increased as development and profit also increased. From my use of various agile methods, I've found a common set of 10 key principles of agile. These are characteristics make agile fundamentally different to previous methods to software development.
They are:
They are:
- Active user involvement is imperative
- The team must be empowered to make decisions
- Requirements evolve but the timescale is fixed
- Capture requirements at a high level; lightweight & visual
- Develop small, incremental releases and iterate
- Focus on frequent delivery of products
- Complete each feature before moving on to the next
- Apply the 80/20 rule
- Testing is integrated throughout the project lifecycle – test early and often
- A collaborative & cooperative approach between all stakeholders is essential
There are various methodologies that are collectively known as agile, as they promote the values of the agile manifesto and they are consistent with the above principles. The most popular ones are:
- DSDM is probably the original agile development method. DSDM was around before the term ‘agile’ was even invented, but is absolutely based on all the principles we’ve come to know as agile. DSDM seems to be much less well-known outside of the UK.
- Scrum is also an agile development method, which concentrates particularly on how to manage tasks within a team-based development environment. Scrum is the most popular and widely adopted agile method – I think because it is relatively simple to implement and addresses many of the management issues that have plagued IT development teams for decades.
- XP (Extreme Programming) is a more radical agile methodology, focusing more on the software engineering process and addressing the analysis, development and test phases with novel approaches that make a substantial difference to the quality of the end product.
Over the last 10 years, there is an ever-increasing volume of success stories, where companies have dramatically improved the success and performance of their IT development teams and projects. This has caused agile to be widely adopted across a variety of industries, including media and technology, large corporates, and even government. In reality, though, agile is not a magic bullet for all software development issues. The real trick is to know lots of techniques from various waterfall and agile development methods, and to select a mixture of the best approaches that are most appropriate for any given situation.
To do this reliably with any degree of success really requires a lot of experience and skill. In agile software projects, project management takes a slightly different form, relying far more on the project manager’s skills in communication, facilitation, coordination, and emphasising far less on planning and control. Agile development can be a very exciting and invigorating approach, although some projects suit agile more than others.
The collaboration and visibility can provide a much richer and more rewarding experience for teams to develop great software products. Agile development can be a lot more enjoyable than the waterfall approach, which requires lots more documentation and is less flexible by its nature.
You don't get one with out loosing from the other however. Less documentation, no matter how you approach the project from start -- requires greater learning curves for new developers coming in cold. Waterfall limits 'project creep' and is far easier to budget and sell.
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