It’s easy to get confused or overly concerned about measuring velocity. Actually, the concept is almost embarrassingly simple. Velocity in Agile is simply the number of units of work completed in a certain interval. Like in many fields, Agile proponents appropriated existing terminology.
Here is one typical definition, from agilesoftwaredevelopment.com:
In Scrum, Velocity is how much product backlog effort a team can handle in one Sprint. Velocity is usually measured in story points or ideal days per Sprint… This way, if the team delivered software for 30 story points in the last Sprint their Velocity is 30.
Velocity as a capacity planning tool used in Agile software development is calculated from the results of several completed sprints. This velocity is then used in planning future sprints.
Scope creep is a frequent topic of discussion among project management professionals. A recent Project Management Institute (PMI)® i Community Post, Fighting the Dreaded Scope Creep, reported some responses PMI members offered as their weapon of choice. The various suggestions can be summarized by two general practices:
Sizing is arguably the most challenging part of any software estimate:
Without a notion of functional size, managers may find it difficult to negotiate realistic schedules based on their demonstrated ability to deliver software. They are unable to show empirically why the twelve person team that worked so well on a 150,000 ESLOC project over six months not only fails to deliver a 75,000 ESLOC project in half the time, but produces an error-ridden product that infuriates the customer. Unlike manufacturing shoes, software development is full of non-linear relationships between size, time, effort, and defects. What data driven estimation does successfully is arm managers with the ability to sanity check their current plans against past performance and negotiate achievable outcomes based on a realistic assessment of how much functionality can be built with a set time frame and resource profile.