One of our most viewed blog entries is PDLC or SDLC, while we don’t know definitively why we suspect that technology leaders are looking for ways to improve their organization’s performance e.g. better quality, faster development. etc. Additionally, we often get asked the question “what is the best software development methodology?” or “should we change PDLC’s?” The simple answer is that there is no “best” and changing methodologies is not likely to fix organizational or process problems. What I’d like to do in this posts is 1) give you a very brief overview of the different methodologies – consider this a primer, a refresher, or feel free to skip and 2) provide a framework for considering which methodology is right for your organization.
The waterfall model is an often used software development processes that occurs in a sequential set of steps. Progress is seen as flowing steadily downwards (like a waterfall) through the phases such as Idea, Analysis, Design, Development, Testing, Implementation and Maintenance. The waterfall development model originated in the hardware manufacturing arena where after-the-fact changes are prohibitively costly. Since no formal software development methodologies existed at the time, this hardware-oriented model was adapted for software development. There are many variations on the waterfall methodology that changes the phases but all have the similar quality of a sequential set of steps. Some waterfall variations include those from Six Sigma (DMAIC, DMADV).
Agile software development is a group of software development methodologies based on iterative and incremental development. The requirements and ultimate products or services that get delivered evolve through collaboration between self-organizing, cross-functional teams. This methodology promotes adaptive planning, evolutionary development and delivery. The Agile Manifesto was introduced in 2001 and introduced a conceptual framework that promotes foreseen interactions throughout the development cycle. The time boxed iterative approach encourages rapid and flexible response to change. There are many variations of Agile including XP, Scrum, FDD, DSDM, and RUP.
With so many different methodologies available how do you decide which is right for your team? Here are a few questions that will help guide you through the decision.
1) Is the business willing to be involved in the entire product development cycle? This involvement takes the form of dedicated resources (no split roles such as running a P&L by day and being a product manager by night), everyone goes through training, and joint ownership of the product / service (no blaming technology for slow delivery or quality problems).
YES – Consider any of the agile methodologies.
NO – Bypass all forms of agile. All of these require commitment and involvement by the business in order to be successful.
2) What is the size of your development teams? Is the entire development team less than 10 people or have you divided the code into small components / services that teams of less than 10 people own and support?
YES – Consider XP or Scrum flavors of the agile methodology.
NO – Consider FDD and DSDM which are capable of scaling up to 100 developers. If you team is even larger consider RUP. Note that with agile, when the development team gets larger so does the amount of documentation and communication and this tends to make the project less agile.
3) Are your teams located in the same location?
YES – Consider any flavor of agile.
NO – While remote teams can and do follow agile methodologies it is much more difficult. If the business owners are not collocated with the developers I would highly recommend sticking with a waterfall methodology.
4) Are you hiring a lot of developers?
YES – Consider the more popular forms of agile or waterfall to minimize the ramp up time of new developers coming on board. If you really want an agile methodology, consider XP which includes paired programming as a concept, and is a good way to bring new developers up to speed quickly.
NO – Any methodology is fine.
A last important idea is that it isn’t important to follow a pure flavor of any methodology. Purist or zealots of process or technology are dangerous because a single tool in your tool box doesn’t provide the flexibility needed in the real world. Feel free to mix or alter concepts of any methodology to make it fit better in your organization or the service being provided.
There are of course counter examples to every one of these questions, in fact I can probably give the examples from our client list. These questions/answers are not definitive but they should provide a starting point or framework for how you can determine your team’s development methodology.