Time-boxing is an important aspect of Scrum. By allotting time boxes and by strictly adhering to these, Scrum teams pave a smooth and a systematic way to success.
Importance of Time boxing in Scrum can be gauged from the fact that development takes place during Sprints – a Sprint is a time boxed unit of development during which the team works on developing features that should be demo ready and potentially shippable at the end of that Sprint. The list of features to be developed during a Sprint is recorded in the form of a Sprint Backlog; however, if the team is unable to finish the amount of work decided upon, they cannot edit the Sprint Backlog. Instead, the unfinished items are left out and returned to the Product Backlog. Therefore, Scrum works on the dictum of time-boxed Sprints.
Time-boxed Sprints contribute greatly toward meeting deadlines and achieving high levels of productivity. Sprints promote order and consistency in a volatile work environment. They provide a platform to gauge results and obtain feedback in a short span of time. Sprints also allow for frequent assessment of progress and the methods used to manage the project, including effective change management. Errors or problems can be identified early and can be rectified quickly.
By using Time-boxing in Sprints, the team frequently revisits the process of estimating the work to be done, so the projection of time and effort required becomes more accurate with each subsequent Sprint as the project progresses. These iterative cycles also motivate team members to achieve projected targets and incremental goals toward reaching the larger objective.
In Scrum, each Sprint is preceded by Sprint Planning Meeting and culminates with a Retrospect Sprint Meeting. Sprint Planning Session is time boxed to eight hours for a 4 week sprint, while Sprint Retrospective is time boxed to four hours for a 4 week sprint. All the teams implementing Scrum adhere to these rules. This not only results in efficient working, but also reduces overhead management and slack on part of the team members.
Another Scrum activity that is strictly time boxed is the Daily Scrum Meeting. Scrum encourages the team members to meet daily, but for not more than 15 minutes. The team members are required to exchange information among themselves on the following three questions:
1. What have you done since yesterday?
2. What are you planning to do today?
3. Any impediments/stumbling blocks?
Daily Scrums are a platform for the exchange of information; these are strictly not meant for discussing problems or for trying to figure out the solutions for these problems. If the team members extend the meeting beyond the stipulated time, these meetings are at a risk to become discussion forums. This not only consumes substantial amounts of time and energy but also puts other important activities on hold; thus, effecting the entire loop. So, if the teams adhere to the set norms, and time box the daily scrum to 15 minutes, it is a great practice.
Hence, time-boxing is an important aspect of Scrum because the underlying norm is that the teams adopting Scrum have to be agile enough to adapt quickly to the fluctuating business and technological scenarios by incorporating planning and modifying requirements in order to release client-valued potentially shippable software features on time and in budget. Thus, Scrum relies on time-boxing to limit scope, to accelerate the speed of product delivery, and to enhance team productivity.