Agile vs waterfall
Waterfall plans the whole project up front and moves through fixed phases. Agile works in short cycles, shows something working each time and changes the plan as it learns.
Two ways to run a project
Waterfall
- Clear plan, scope and price up front
- Good when requirements are fixed
- Late feedback
- Changes are costly
Agile
- Working results every few weeks
- Changes welcome
- Needs a customer who takes part
- Scope and cost are less certain
When waterfall works
When requirements are stable and mistakes are expensive to fix later, such as building construction, regulated products or a fixed-price contract with a precise specification.
When agile works
When you learn what is needed by building it, as with most software and product work. Short cycles turn wrong guesses into small, cheap corrections.
Mixing them
Many teams plan the budget and milestones up front and run the work in sprints. What matters is that feedback arrives while changing course is still cheap.
Questions
Is agile faster?
Not always; it delivers useful results earlier and reduces the risk of building the wrong thing.
What is a sprint?
A fixed period, usually one to four weeks, with a goal that ends in something working and a review.
Does agile mean no planning?
No. It plans in smaller pieces and re-plans often.
Can a fixed-price project be agile?
Yes, by fixing the budget and the time and letting the scope flex within them.