A Gantt chart is a bar chart that illustrates a project schedule. It was designed and popularized by Henry Gantt around the years 1910–1915.[1][2] Modern Gantt charts also show the dependency relationships between activities and the current schedule status.
A Gantt chart showing three kinds of schedule dependencies (in red) and percent complete indications.
A Gantt chart is a type of bar chart[3][4] that illustrates a project schedule.[5] This chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis.[3][6] The width of the horizontal bars in the graph shows the duration of each activity.[6][7] Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements constitute the work breakdown structure of the project. Modern Gantt charts also show the dependency (i.e., precedence network) relationships between activities. Gantt charts can be used to show current schedule status using percent-complete shadings and a vertical "TODAY" line.
Gantt charts are sometimes equated with bar charts.[7][8]
Gantt charts are usually created initially using an early start time approach, where each task is scheduled to start immediately when its prerequisites are complete. This method maximizes the float time available for all tasks.[3]
History
Although widely used in project planning in the present day, Gantt charts were considered revolutionary when introduced.[9] The first known tool of this type was developed in 1896 by Karol Adamiecki, who called it a harmonogram.[10] Adamiecki, however, published his chart only in Russian and Polish which limited both its adoption and recognition of his authorship.
In 1912, Hermann Schürch [de] published what could be considered Gantt charts while discussing a construction project. Charts of the type published by Schürch appear to have been in common use in Germany at the time;[11][12][13] however, the prior development leading to Schürch's work is unclear.[14] Unlike later Gantt charts, Schürch's charts did not display interdependencies, leaving them to be inferred by the reader. These were also static representations of a planned schedule.[15]
The chart is named after Henry Gantt (1861–1919), who designed his chart around the years 1910–1915.[1][2] Gantt originally created his tool for systematic, routine operations. He designed this visualization tool to more easily measure productivity levels of employees and gauge which employees were under- or over-performing. Gantt also frequently included graphics and other visual indicators in his charts to track performance. [16]
The earliest Gantt charts were drawn on paper and therefore had to be redrawn entirely in order to adjust to schedule changes. For many years, project managers used pieces of paper or blocks for Gantt chart bars so they could be adjusted as needed.[18] Gantt's collaborator Walter Polakov introduced Gantt charts to the Soviet Union in 1929 when he was working for the Supreme Soviet of the National Economy. They were used in developing the First Five Year Plan, supplying Russian translations to explain their use.[19][20]
In the 1980s, personal computers allowed widespread creation of complex and elaborate Gantt charts. The first desktop applications were intended mainly for project managers and project schedulers. With the advent of the Internet and increased collaboration over networks at the end of the 1990s, Gantt charts became a common feature of web-based applications, including collaborative groupware.[citation needed] By 2012, almost all Gantt charts were made by software which can easily adjust to schedule changes.[18]
In 1999, Gantt charts were identified as "one of the most widely used management tools for project scheduling and control".[3]
Example
In the following tables there are seven tasks, labeled a through g. Some tasks can be done concurrently (a and b) while others cannot be done until their predecessor task is complete (c and d cannot begin until a is complete). Additionally, each task has three time estimates: the optimistic time estimate (O), the most likely or normal time estimate (M), and the pessimistic time estimate (P). The expected time (TE) is estimated using the beta probability distribution for the time estimates, using the formula (O + 4M + P) ÷ 6.
Activity
Predecessor
Time estimates (in days)
Expected time (TE)
Opt. (O)
Normal (M)
Pess. (P)
a
—
2
4
6
4.00
b
—
3
5
9
5.33
c
a
4
5
7
5.17
d
a
4
6
10
6.33
e
b, c
4
5
7
5.17
f
d
3
4
8
4.50
g
e
3
5
8
5.17
Once this step is complete, one can draw a Gantt chart or a network diagram.
A Gantt chart created using Microsoft Project. Note (1) the critical path is in red, (2) the slack is the black lines connected to non-critical activities, (3) since Saturday and Sunday are not work days and are thus excluded from the schedule, some bars on the Gantt chart are longer if they cut through a weekend.
Progress Gantt charts
In a progress Gantt chart, tasks are shaded in proportion to the degree of their completion: a task that is 60% complete would be 60% shaded, starting from the left. A vertical line is drawn at the time index when the progress Gantt chart is created, and this line can then be compared with shaded tasks. If everything is on schedule, all task portions left of the line will be shaded, and all task portions right of the line will not be shaded. This provides a visual representation of how the project and its tasks are ahead or behind schedule.[21]
Linked Gantt charts
Linked Gantt charts contain lines indicating the dependencies between tasks. However, linked Gantt charts quickly become cluttered in all but the simplest cases. Critical path network diagrams are superior to visually communicate the relationships between tasks.[22] Nevertheless, Gantt charts are often preferred over network diagrams because Gantt charts are easily interpreted without training, whereas critical path diagrams require training to interpret.[8] Gantt chart software typically provides mechanisms to link task dependencies, although this data may or may not be visually represented.[3] Gantt charts and network diagrams are often used for the same project, both being generated from the same data by a software application.[3]
^Kumar, Pankaja Pradeep (2005). "Effective Use of Gantt Chart for Managing Large Scale Projects". Cost Engineering. Morgantown, WV: American Association of Cost Engineers. 47 (7): 13–21. ISSN 0274-9696. OCLC 209778284.
^Geraldi, Joana; Lechter, Thomas (2012). "Gantt charts revisited". International Journal of Managing Projects in Business. 5 (4): 578-594. doi:10.1108/17538371211268889.
^Kelly, D. J. (2004) "Marxist Manager Amidst the Progressives: Walter N. Polakov and the Taylor Society", Journal of Industrial History, 6(2), November 2004, 61-75
^Olson, Richard G. (2015). Scientism and Technocracy in the Twentieth Century: The Legacy of Scientific Management. Lexington Books. ISBN9781498525718. Retrieved 25 September 2018.
Clark, Wallace (1922). The Gantt Chart: A Working Tool of Management. New York, NY: Ronald Press.
Flouris, Triant G.; Lock, Dennis (2012). Managing Aviation Projects from Concept to Completion. Ashgate Publishing Limited. ISBN978-1-4094-8613-8.
Gantt, H.L. (1910). "Work, Wages and Profit". Engineering Magazine. New York.; republished as Work, Wages and Profits. Easton, Pennsylvania: Hive Publishing Company. 1974. ISBN0-87960-048-9.
Klein, R. (1999). Scheduling of Resource-Constrained Projects. Operations Research/Computer Science Interfaces Series. Springer US. ISBN978-0-7923-8637-7.
Marsh, Edward R. (1974). "The Harmonogram of Karol Adamiecki". Academy of Management Proceedings. 1974: 32. doi:10.5465/ambpp.1974.17530521. ISSN 0065-0668.
Morris, Peter W. G. (1997) [1994]. The Management of Projects. Thomas Telford. ISBN978-0-7277-2593-6.
Richman, L. (2002). Project Management Step-by-step. Amacom. p. 117. ISBN978-0-8144-2657-9.
Selig, Gad J. (2008). Implementing IT Governance: A Practical Guide to Global Best Practices in IT Management. Van Haren Publishing. ISBN978-90-8753-774-6.
Weaver, Patrick (2012a). "Henry L Gantt, 1861–1919: A retrospective view of his work" (PDF). PM World Journal. Retrieved 29 January 2018. (It is unclear when this was last modified. The PDF metadata indicates 2015, and a note in the text says "Augmented with additional materials received since publication".)
Weaver, Patrick (2012b). "Henry L Gantt, 1861–1919: Debunking the myths, a retrospective view of his work" (PDF). 1 (5). Retrieved 29 January 2018. {{cite journal}}: Cite journal requires |journal= (help)
Weaver, Patrick (2017). "A Brief History of Scheduling: Back to the Future" (PDF). Retrieved 29 January 2018. {{cite journal}}: Cite journal requires |journal= (help) Adapted from "A Brief History of Scheduling: Back to the Future" (PDF). PM World Journal. 3 (8). 2014. Adapted from an even earlier 2006 presentation.
Wilson, James M. (2003). (PDF). European Journal of Operational Research. 149 (2): 430–437. doi:10.1016/S0377-2217(02)00769-5. Archived from the original (PDF) on 26 November 2013. Retrieved 28 July 2013.
Further reading
Burkhard, Remo Aslak; Meier, Michael; Rodgers, Peter; Smis, Matthias Thomas Jelle; Stott, Jonathan (2005). Knowledge visualization: A comparative study between Project Tube Maps and Gantt Charts. 5th International Conference on Knowledge Management. Graz, Austria: University of Kent. Retrieved 17 September 2017.
Geraldi, Joana; Lechter, Thomas (2012). "Gantt charts revisited: A critical analysis of its roots and implications to the management of projects today". International Journal of Managing Projects in Business. 5 (4): 578–594. doi:10.1108/17538371211268889.
Kumar, Pankaja Pradeep (2005). "Effective use of Gantt chart for managing large scale projects". Cost Engineering. 47 (7): 14–21. ISSN 0274-9696. Retrieved 17 September 2017.
Marsh, Edward R. (1975). "The Harmonogram of Karol Adamiecki". Academy of Management Journal. 18 (2): 358–364. doi:10.2307/255537. JSTOR 255537.
Maylor, Harvey (2001). "Beyond the Gantt chart: Project management moving on". European Management Journal. 19 (1): 92–100. doi:10.1016/S0263-2373(00)00074-8. S2CID 153555271.
Schürch, Hermann (1915), "Der Bau des Talüberganges bei Langwies an der elektrischen Bahn Chur-Arosa" [The construction of the valley crossing at Langwies of the Chur-Arosa electric railway line] (PDF), Armierter Beton: Monatsschrift für Theorie und Praxis des gesamten Betonbaues (Reinforced concrete: Monthly for theory and practice of the entire concrete construction) (in German), Berlin: Springer, vol. 8, no. 10, pp. 229–238, retrieved 29 January 2018
Virine, Lev & Trumper, Michael (2013), ProjectThink. Why Good Managers Make Poor Project Choices, Gower Pub Co., ISBN978-1409454984{{citation}}: CS1 maint: multiple names: authors list (link)
Virine, Lev & Trumper, Michael (2017), Project Risk Analysis Made Ridiculously Simple, World Scientific Publishing, ISBN978-9814759373{{citation}}: CS1 maint: multiple names: authors list (link)
Weaver, Patrick. "Henry L. Gantt: A Retrospective view of his work". Retrieved 29 January 2018.
Weaver, Patrick. "A Brief History of Scheduling".
External links
Wikimedia Commons has media related to Gantt charts.
Look up gantt chart in Wiktionary, the free dictionary.
Long-running discussion regarding limitations of the Gantt chart format, and alternatives, on Edward Tufte's website
March 22, 2023
gantt, chart, chart, that, illustrates, project, schedule, designed, popularized, henry, gantt, around, years, 1910, 1915, modern, also, show, dependency, relationships, between, activities, current, schedule, status, showing, three, kinds, schedule, dependenc. A Gantt chart is a bar chart that illustrates a project schedule It was designed and popularized by Henry Gantt around the years 1910 1915 1 2 Modern Gantt charts also show the dependency relationships between activities and the current schedule status A Gantt chart showing three kinds of schedule dependencies in red and percent complete indications Henry Gantt inventor of the Gantt chart Contents 1 Definition 2 History 3 Example 4 Progress Gantt charts 5 Linked Gantt charts 6 See also 7 Citations 8 References 9 Further reading 10 External linksDefinition EditA Gantt chart is a type of bar chart 3 4 that illustrates a project schedule 5 This chart lists the tasks to be performed on the vertical axis and time intervals on the horizontal axis 3 6 The width of the horizontal bars in the graph shows the duration of each activity 6 7 Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project Terminal elements and summary elements constitute the work breakdown structure of the project Modern Gantt charts also show the dependency i e precedence network relationships between activities Gantt charts can be used to show current schedule status using percent complete shadings and a vertical TODAY line Gantt charts are sometimes equated with bar charts 7 8 Gantt charts are usually created initially using an early start time approach where each task is scheduled to start immediately when its prerequisites are complete This method maximizes the float time available for all tasks 3 History EditAlthough widely used in project planning in the present day Gantt charts were considered revolutionary when introduced 9 The first known tool of this type was developed in 1896 by Karol Adamiecki who called it a harmonogram 10 Adamiecki however published his chart only in Russian and Polish which limited both its adoption and recognition of his authorship In 1912 Hermann Schurch de published what could be considered Gantt charts while discussing a construction project Charts of the type published by Schurch appear to have been in common use in Germany at the time 11 12 13 however the prior development leading to Schurch s work is unclear 14 Unlike later Gantt charts Schurch s charts did not display interdependencies leaving them to be inferred by the reader These were also static representations of a planned schedule 15 The chart is named after Henry Gantt 1861 1919 who designed his chart around the years 1910 1915 1 2 Gantt originally created his tool for systematic routine operations He designed this visualization tool to more easily measure productivity levels of employees and gauge which employees were under or over performing Gantt also frequently included graphics and other visual indicators in his charts to track performance 16 One of the first major applications of Gantt charts was by the United States during World War I at the instigation of General William Crozier 17 The earliest Gantt charts were drawn on paper and therefore had to be redrawn entirely in order to adjust to schedule changes For many years project managers used pieces of paper or blocks for Gantt chart bars so they could be adjusted as needed 18 Gantt s collaborator Walter Polakov introduced Gantt charts to the Soviet Union in 1929 when he was working for the Supreme Soviet of the National Economy They were used in developing the First Five Year Plan supplying Russian translations to explain their use 19 20 In the 1980s personal computers allowed widespread creation of complex and elaborate Gantt charts The first desktop applications were intended mainly for project managers and project schedulers With the advent of the Internet and increased collaboration over networks at the end of the 1990s Gantt charts became a common feature of web based applications including collaborative groupware citation needed By 2012 almost all Gantt charts were made by software which can easily adjust to schedule changes 18 In 1999 Gantt charts were identified as one of the most widely used management tools for project scheduling and control 3 Example EditIn the following tables there are seven tasks labeled a through g Some tasks can be done concurrently a and b while others cannot be done until their predecessor task is complete c and d cannot begin until a is complete Additionally each task has three time estimates the optimistic time estimate O the most likely or normal time estimate M and the pessimistic time estimate P The expected time TE is estimated using the beta probability distribution for the time estimates using the formula O 4M P 6 Activity Predecessor Time estimates in days Expected time TE Opt O Normal M Pess P a 2 4 6 4 00b 3 5 9 5 33c a 4 5 7 5 17d a 4 6 10 6 33e b c 4 5 7 5 17f d 3 4 8 4 50g e 3 5 8 5 17Once this step is complete one can draw a Gantt chart or a network diagram A Gantt chart created using Microsoft Project Note 1 the critical path is in red 2 the slack is the black lines connected to non critical activities 3 since Saturday and Sunday are not work days and are thus excluded from the schedule some bars on the Gantt chart are longer if they cut through a weekend Progress Gantt charts EditIn a progress Gantt chart tasks are shaded in proportion to the degree of their completion a task that is 60 complete would be 60 shaded starting from the left A vertical line is drawn at the time index when the progress Gantt chart is created and this line can then be compared with shaded tasks If everything is on schedule all task portions left of the line will be shaded and all task portions right of the line will not be shaded This provides a visual representation of how the project and its tasks are ahead or behind schedule 21 Linked Gantt charts EditLinked Gantt charts contain lines indicating the dependencies between tasks However linked Gantt charts quickly become cluttered in all but the simplest cases Critical path network diagrams are superior to visually communicate the relationships between tasks 22 Nevertheless Gantt charts are often preferred over network diagrams because Gantt charts are easily interpreted without training whereas critical path diagrams require training to interpret 8 Gantt chart software typically provides mechanisms to link task dependencies although this data may or may not be visually represented 3 Gantt charts and network diagrams are often used for the same project both being generated from the same data by a software application 3 See also EditCritical path method Data and information visualization Event chain methodology Float project management List of project management software which includes specific Gantt chart software Program evaluation and review technique PERT Event chain diagramCitations Edit a b Gantt 1910 a b Morris 1997 p 7 a b c d e f Klein 1999 p 49 Richman 2002 pp 97 117 276 Kumar Pankaja Pradeep 2005 Effective Use of Gantt Chart for Managing Large Scale Projects Cost Engineering Morgantown WV American Association of Cost Engineers 47 7 13 21 ISSN 0274 9696 OCLC 209778284 a b Richman 2002 pp 117 276 a b Selig 2008 p 235 a b Flouris amp Lock 2012 p 236 Chapter 12 Wilson 2003 Marsh 1974 p 32 Weaver 2012a pp 5 6 Weaver 2012b pp 4 6 Weaver 2017 pp 6 7 Weaver 2017 p 7 Weaver 2017 p 6 Geraldi Joana Lechter Thomas 2012 Gantt charts revisited International Journal of Managing Projects in Business 5 4 578 594 doi 10 1108 17538371211268889 Clark 1922 a b Flouris amp Lock 2012 p 281 Chapter 14 Kelly D J 2004 Marxist Manager Amidst the Progressives Walter N Polakov and the Taylor Society Journal of Industrial History 6 2 November 2004 61 75 Olson Richard G 2015 Scientism and Technocracy in the Twentieth Century The Legacy of Scientific Management Lexington Books ISBN 9781498525718 Retrieved 25 September 2018 Klein 1999 pp 56 57 Flouris amp Lock 2012 p 239 Chapter 12 References EditClark Wallace 1922 The Gantt Chart A Working Tool of Management New York NY Ronald Press Flouris Triant G Lock Dennis 2012 Managing Aviation Projects from Concept to Completion Ashgate Publishing Limited ISBN 978 1 4094 8613 8 Gantt H L 1910 Work Wages and Profit Engineering Magazine New York republished as Work Wages and Profits Easton Pennsylvania Hive Publishing Company 1974 ISBN 0 87960 048 9 Klein R 1999 Scheduling of Resource Constrained Projects Operations Research Computer Science Interfaces Series Springer US ISBN 978 0 7923 8637 7 Marsh Edward R 1974 The Harmonogram of Karol Adamiecki Academy of Management Proceedings 1974 32 doi 10 5465 ambpp 1974 17530521 ISSN 0065 0668 Morris Peter W G 1997 1994 The Management of Projects Thomas Telford ISBN 978 0 7277 2593 6 Richman L 2002 Project Management Step by step Amacom p 117 ISBN 978 0 8144 2657 9 Selig Gad J 2008 Implementing IT Governance A Practical Guide to Global Best Practices in IT Management Van Haren Publishing ISBN 978 90 8753 774 6 Weaver Patrick 2012a Henry L Gantt 1861 1919 A retrospective view of his work PDF PM World Journal Retrieved 29 January 2018 It is unclear when this was last modified The PDF metadata indicates 2015 and a note in the text says Augmented with additional materials received since publication Weaver Patrick 2012b Henry L Gantt 1861 1919 Debunking the myths a retrospective view of his work PDF 1 5 Retrieved 29 January 2018 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Weaver Patrick 2017 A Brief History of Scheduling Back to the Future PDF Retrieved 29 January 2018 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Adapted from A Brief History of Scheduling Back to the Future PDF PM World Journal 3 8 2014 Adapted from an even earlier 2006 presentation Wilson James M 2003 Gantt charts A centenary appreciation PDF European Journal of Operational Research 149 2 430 437 doi 10 1016 S0377 2217 02 00769 5 Archived from the original PDF on 26 November 2013 Retrieved 28 July 2013 Further reading EditBurkhard Remo Aslak Meier Michael Rodgers Peter Smis Matthias Thomas Jelle Stott Jonathan 2005 Knowledge visualization A comparative study between Project Tube Maps and Gantt Charts 5th International Conference on Knowledge Management Graz Austria University of Kent Retrieved 17 September 2017 Geraldi Joana Lechter Thomas 2012 Gantt charts revisited A critical analysis of its roots and implications to the management of projects today International Journal of Managing Projects in Business 5 4 578 594 doi 10 1108 17538371211268889 Kumar Pankaja Pradeep 2005 Effective use of Gantt chart for managing large scale projects Cost Engineering 47 7 14 21 ISSN 0274 9696 Retrieved 17 September 2017 Marsh Edward R 1975 The Harmonogram of Karol Adamiecki Academy of Management Journal 18 2 358 364 doi 10 2307 255537 JSTOR 255537 Maylor Harvey 2001 Beyond the Gantt chart Project management moving on European Management Journal 19 1 92 100 doi 10 1016 S0263 2373 00 00074 8 S2CID 153555271 Schurch Hermann 1915 Der Bau des Taluberganges bei Langwies an der elektrischen Bahn Chur Arosa The construction of the valley crossing at Langwies of the Chur Arosa electric railway line PDF Armierter Beton Monatsschrift fur Theorie und Praxis des gesamten Betonbaues Reinforced concrete Monthly for theory and practice of the entire concrete construction in German Berlin Springer vol 8 no 10 pp 229 238 retrieved 29 January 2018 Virine Lev amp Trumper Michael 2013 ProjectThink Why Good Managers Make Poor Project Choices Gower Pub Co ISBN 978 1409454984 a href Template Citation html title Template Citation citation a CS1 maint multiple names authors list link Virine Lev amp Trumper Michael 2017 Project Risk Analysis Made Ridiculously Simple World Scientific Publishing ISBN 978 9814759373 a href Template Citation html title Template Citation citation a CS1 maint multiple names authors list link Weaver Patrick Henry L Gantt A Retrospective view of his work Retrieved 29 January 2018 Weaver Patrick A Brief History of Scheduling External links Edit Wikimedia Commons has media related to Gantt charts Look up gantt chart in Wiktionary the free dictionary Long running discussion regarding limitations of the Gantt chart format and alternatives on Edward Tufte s website Retrieved from https en wikipedia org w index php title Gantt chart amp oldid 1139942621, wikipedia, wiki, book, books, library,
