Timeboxing

Timeboxing is used as a project planning technique. The schedule is divided into a number of separate time periods (timeboxes), with each part having its own deliverables, deadline and budget.{{Citation needed|date=November 2011}} Sometimes referred to as schedule as independent variable (SAIV).{{Cite book|url=https://books.google.com/books?id=MWhXwkHsS0gC&q=%22Schedule+as%22&pg=PA212|title=Balancing Agility and Discipline: A Guide for the Perplexed|last1=Boehm|first1=Barry W.|last2=Boehm|first2=Barry|last3=Turner|first3=Richard|date=2004|publisher=Addison-Wesley Professional|isbn=9780321186126|language=en}} "Timeboxing works best in multistage projects or tasks that take little time and you can fit them in the same time slot. It is also worth implementing in case of duties that have foreseeable time-frames of completion."{{Cite web|date=2022-01-17|title=Timeboxing – why you should use it?|url=https://firmbee.com/timeboxing-why-you-should-use-it/|access-date=2022-01-25|website=Firmbee|language=en}}

In project management, there are generally considered to be three constraints: time (sometimes schedule), cost (sometimes budget), and scope.[http://www.projectmanagement.net.au/triple_constraints What are the Triple Constraints in Project Management] {{webarchive|url=https://archive.today/20060820021929/http://www.projectmanagement.net.au/triple_constraints |date=2006-08-20 }}, article by Rod Hutchings on [http://projectmanagement.net.au/ Project Management Australia] {{webarchive|url=https://web.archive.org/web/20090216052557/http://projectmanagement.net.au/ |date=2009-02-16 }} (22 Oct 2008){{Cite news| first=Carl | last=Chatfield | title=A short course in project management | url=http://office.microsoft.com/en-us/project/HA102354821033.aspx| publisher=Microsoft}}{{cite book | last = Dobson | first = Michael | title = The triple constraints in project management | publisher = Management Concepts | location = Vienna, Va | year = 2004 | isbn = 1-56726-152-3 }} (Quality is often added as a fourth constraint---represented as the middle of a triangle.{{cite book |last= Snedaker |first= Susan |author2=Nels Hoenig |title= How to Cheat at IT Project Management |publisher= Syngress |year= 2005 |isbn= 1-59749-037-7 }}{{cite book | last = Beck | first = Kent | title = Extreme programming eXplained: embrace change | publisher = Addison-Wesley | location = Reading, MA | year = 2000 | isbn = 0-201-61641-6 | pages = [https://archive.org/details/extremeprogrammi00beck/page/15 15]–19 | url = https://archive.org/details/extremeprogrammi00beck | url-access = limited }}{{cite book | last = Dangelo | first = Mark | title = Innovative relevance: realigning the organization for profit: it is not a battle for the "shore lines" - it's a struggle for purpose | publisher = iUniverse | location = New York | year = 2005 | isbn = 978-0-595-67081-9 | page=53 | url=https://books.google.com/books?id=LQx3lab0KnIC}}) The assumption is that a change in one constraint will affect the others.{{cite book | last = Kanabar | first = Vijay | title = MBA Fundamentals: Project Management | publisher = Kaplan Pub | location = New York | year = 2008 | page = 51 | isbn = 978-1-4277-9744-5 }}

Without timeboxing, projects usually work to a fixed scope,{{cite book |last= Godin |first= Seth |title= Getting Real: The smarter, faster, easier way to build a successful web application |publisher= 37signals }} in which case when it becomes clear that some deliverables cannot be completed within the planned timescales, either the deadline has to be extended (to allow more time to complete the fixed scope) or more people are involved (to complete the fixed scope in the same time). Often both happen, resulting in delayed delivery, increased costs, and often reduced quality (as per The Mythical Man-Month principle).

With timeboxing, the deadline is fixed, meaning that the scope would have to be reduced. As this means organizations have to focus on completing the most important deliverables first, timeboxing often goes hand-in-hand with a scheme for prioritizing of deliverables (such as with the MoSCoW method).{{Cite book|title=DSDM, dynamic systems development method: the method in practice|last=Jennifer.|first=Stapleton|date=1997|publisher=Addison-Wesley|isbn=0201178893|location=Harlow, England|oclc=36755892}}

Timeboxes are used as a form of risk management, to explicitly identify uncertain task/time relationships, i.e., work that may easily extend past its deadline. Time constraints are often a primary driver in planning and should not be changed without considering project or sub-project critical paths. That is, it's usually important to meet deadlines. Risk factors for missed deadlines can include complications upstream of the project, planning errors within the project, team-related issues, or faulty execution of the plan. Upstream issues might include changes in project mission or backing/support from management. A common planning error is inadequate task breakdown, which can lead to underestimation of the time required to perform the work. Team-related issues can include trouble with inter-team communication; lack of experience or required cross-functionality; lack of commitment/drive/motivation (i.e. poor team building and management).

To stay on deadline, the following actions against the triple constraints are commonly evaluated:

• Reduce scope: drop requirements of lower impact (the ones that will not be directly missed by the user)
• Time is the fixed constraint here
• Increase cost: e.g., add overtime or resources

Many successful software development projects use timeboxing, especially smaller ones.For all project types time boxing ranked 23 and rated "Very Good Practice"; for small (1000 function point) projects ranked 7 and rated a "Best Practice" by the survey in {{cite book | last = Jones | first = Capers | title = Software engineering best practices lessons from successful projects in the top companies | publisher = McGraw-Hill | location = New York | year = 2010 | isbn = 978-0-07-162162-5}} Adopting timeboxing more than tripled developer productivity at DuPont in the '80s. In some cases, applications were completely delivered within the time estimated to complete just a specification. However, Steve McConnell argues that not every product is suitable and that timeboxing should only be used after the customer agrees to cut features, not quality. There is little evidence for strong adoption amongst the largest class of projects.

Timeboxing has been adopted by some notable software development methodologies:

• Dynamic systems development method (DSDM).
• In lean software development, pull scheduling with Kanban provides short term time management. When developing a large and complex system, where long term planning is required, timeboxing is layered above.{{cite book | last = Poppendieck | first = Mary | title = Leading Lean Software Development: Results are not the Point | publisher = Addison-Wesley | location = Upper Saddle River, NJ | pages = 137–140 | year = 2010 | isbn = 978-0-321-62070-5 }}
• Rapid application development (RAD) software development process features iterative development and software prototyping. According to Steve McConnell, timeboxing is a "Best Practice" for RAD and a typical timebox length should be 60–120 days.{{cite book | last = McConnell | first = Steve | title = Rapid Development: taming wild software schedules | publisher = Microsoft Press | location = Redmond, Wash | year = 1996 | isbn = 1-55615-900-5 | pages = [https://archive.org/details/rapiddevelopment00mcco/page/575 575]–583 | url = https://archive.org/details/rapiddevelopment00mcco | url-access = limited }}
• Scrum was influenced by ideas of timeboxing and iterative development.{{cite book | last = Coplien | first = James | title = Lean Architecture for Agile Software Development | publisher = Wiley | location = Chichester Hoboken, N.J | year = 2010 | url = https://books.google.com/books?id=lpvY36MPMUwC | page = 25 | isbn = 978-0-470-68420-7 }} Regular timeboxed units known as sprints form the basic unit of development.{{cite book | last = Cohn | first = Mike | title = Succeeding with Agile: Software Development using Scrum | url = https://archive.org/details/succeedingwithag00cohn_599 | url-access = limited | publisher = Addison-Wesley | location = Upper Saddle River, NJ | year = 2010 | pages = [https://archive.org/details/succeedingwithag00cohn_599/page/n284 257]–284 | isbn = 978-0-321-57936-2 }} A typical length for a sprint is less than 30 days.{{cite book | last = Leffingwell | first = Dean | title = Agile Software Requirements: Lean requirements practices for teams, programs, and the enterprise | publisher = Addison-Wesley | location = Upper Saddle River, NJ | year = 2011 | isbn = 978-0-321-63584-6 | pages = 15 | url = https://books.google.com/books?id=pTExbNmZwZUC }} Sprint planning, sprint retrospective and sprint review meetings are timeboxed.{{cite book | last = Schwaber | first = Ken | title = Agile Project Management with Scrum | publisher = O'Reilly Media, Inc | location = New York | year = 2009 | url = https://books.google.com/books?id=RpYX01XVMksC | isbn = 978-0-7356-3790-0 }}
• In Extreme programming methodologies, development planning is timeboxed into iterations typically 1, 2 or 3 weeks in length. The business revalues pending user stories before each iteration.{{cite book | last = Beck | first = Kent | title = Extreme programming eXplained: embrace change | publisher = Addison-Wesley | location = Reading, MA | year = 2000 | isbn = 0-201-61641-6 | pages = [https://archive.org/details/extremeprogrammi00beck/page/85 85]–96 | url = https://archive.org/details/extremeprogrammi00beck | url-access = limited }}

Agile software development advocates moving from plan driven to value driven development. Quality and time are fixed but flexibility allowed in scope. Delivering the most important features first leads to an earlier return on investment than the waterfall model.{{cite book | last = Leffingwell | first = Dean | title = Agile Software Requirements: Lean requirements practices for teams, programs, and the enterprise | publisher = Addison-Wesley | location = Upper Saddle River, NJ | year = 2011 | isbn = 978-0-321-63584-6 | pages = 17–19 | url = https://books.google.com/books?id=pTExbNmZwZUC }}

A lack of detailed specifications typically is the result of a lack of time, or the lack of knowledge of the desired end result (solution). In many types of projects, and especially in software engineering, analyzing and defining all requirements and specifications before the start of the realization phase is impossible. Timeboxing can be a favorable type of contracting for projects in which the deadline is the most critical aspect and when not all requirements are completely specified up front. This also allows for new feedback or insights discovered during the project to be reflected in the end result.

{{Main|Timeblocking}}

Timeboxing can be used for personal tasks, in which case it uses a reduced scale of time (e.g., thirty minutes) and of deliverables (e.g., a household chore instead of project deliverable), and is often called timeblocking.

Personal timeboxing is also said to act as a life hack to help curb perfectionist tendencies (by setting a firm time and not overcommitting to a task) which can also enhance creativity and focus (by creating a sense of urgency or increased pressure).{{cite book | last = Pash | first = Adam | title = Lifehacker the guide to working smarter, faster, and better | publisher = Wiley | location = Indianapolis, Ind | year = 2011 | isbn = 978-1-118-13345-3 | url = https://books.google.com/books?id=d-FYJceblAMC | at=Hack 29}}

Timeboxing acts as a building block in other personal time management methods:

• The Pomodoro Technique is based on 25 minute timeboxes of focused concentration separated by breaks allowing the mind to recover.{{cite book | last=Nöteberg | first=Staffan | title=Pomodoro Technique Illustrated | year=2009 | publisher = Pragmatic Bookshelf | location = Raleigh, N.C | isbn=978-1-934356-50-0 }}
• Andy Hunt gives timeboxing as his 'T' in SMART.{{cite book | last = Hunt | first = Andrew | title = Pragmatic thinking and learning: refactor your wetware | publisher = Pragmatic | location = Raleigh | year = 2008 | isbn = 978-1-934356-05-0 | url = https://archive.org/details/pragmaticthinkin00hunt_1 }}

• Design sprint, a time-constrained five-phase process used in design thinking.

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Category:Time management

Category:Dynamic systems development method

Category:Software project management

Category:Agile software development

Category:Lean manufacturing