Hello.
"A Gantt chart is a horizontal bar chart developed as a production
control tool in 1917 by Henry L. Gantt, an American engineer and
social scientist. Frequently used in project management, a Gantt chart
provides a graphical illustration of a schedule that helps to plan,
coordinate, and track specific tasks in a project. Gantt charts may be
simple versions created on graph paper or more complex automated
versions created using project management applications such as
Microsoft Project or Excel."
From Searchsystemsmanagement.com. See the site for illustration:
http://searchsystemsmanagement.techtarget.com/sDefinition/0,,sid20_gci331397,00.html
From Netmba.com:
"During the era of scientific management, Henry Gantt developed a tool
for displaying the progression of a project in the form of a
specialized chart. An early application was the tracking of the
progress of ship building projects...
The horizontal axis of the Gantt chart is a time scale, expressed
either in absolute time or in relative time referenced to the
beginning of the project. The time resolution depends on the project -
the time unit typically is in weeks or months. Rows of bars in the
chart show the beginning and ending dates of the individual tasks in
the project."
Source Netmba.com:
http://www.netmba.com/operations/project/gantt/
From CET 445 - Construction Planning and Scheduling:
"Advantages of Gantt Chart
* Simple graphic representation of schedule information
* When timescaled, shows operations and the time consumed by them.
* Easily shows the scheduled vs. the actual progress.
Disadvantages of Gantt Charts
* They do not show clear dependencies between activities.
* Although the status of individual activities can be readily
ascertained, the overall status of a project cannot be determined when
some activities are not on schedule"
Hosted by Old Dominion University:
http://www.odu.edu/webroot/instr/et/cconsidi.nsf/pages/cet445lecture1
-----------------------
A "network diagram" (also called a "network schedule") is different
from a Gantt chart in that depicts the interrelationships between the
activities.
"While Gantt charts are very useful the have some drawbacks. Gantt
charts don’t show the interrelationships between tasks. You need a
network diagram for that. Gantt charts also may not show enough detail
for individual team members in a complex project."
From Thebusinessma.com:
http://www.thebusinessmac.com/features/projmgmt5.shtml
"Network Schedules
* Developed in the 1950’ to overcome the shortcomings of the Gantt
Chart.
* CPM (Critical Path Method) & PERT
* Allows for explicit definition of interrelationships among
activities.
* The "Network" shows how activities relate to one another."
http://www.odu.edu/webroot/instr/et/cconsidi.nsf/pages/cet445lecture1
"Network diagram
A diagram showing the tasks in a project, their sequence and the
relationships (links) between them - a 'model' of the project. In the
commonly used precedence diagram, tasks are represented by nodes and
links are represented by lines. Sometimes called a flowchart, PERT
chart, logic drawing, or logic diagram."
From Claremont-controls.co.uk:
http://www.claremont-controls.co.uk/noframes/white/whi009.htm
A PERT chart, an example of a network diagram, is illustrated by
SearchSystemsManagement.com.
"The PERT chart is sometimes preferred over the Gantt chart, another
popular project management charting method, because it clearly
illustrates task dependencies. On the other hand, the PERT chart can
be much more difficult to interpret, especially on complex projects.
Frequently, project managers use both techniques."
http://searchsystemsmanagement.techtarget.com/sDefinition/0,,sid20_gci331391,00.html
-----------------------
A "precedence diagram" is a type of network diagram in which the
activities are illustrated in the nodes of the diagram. The
"precedence diagram" is different from another kind of network diagram
called an "arrow diagram." In the "arrow diagram," the activities are
illustrated by the arrows between the nodes rather than the nodes
themselves. In the "arrow diagram," the nodes depict "events" rather
than activities. The "precedence diagram" is sometimes called an
"activity on node" diagram. Both the "precedence" and "arrow" diagrams
are network diagrams that utilize the "Critical Path Method" (CPM). An
important difference between the CPM and the PERT is that the CPM
assumes precise durations for the activities. PERT assumes the
durations are not precise.
See the web page "Project Management - Network Diagram":
"~Activity - On - Arrow diagram or 'arrow diagram'
~Activity - On - Node diagram or "precedence diagram'
~Arrow diagrams have been used most extensively... Precedence diagrams
are gaining in recognition and use"
From University of Florida. See the site for illustrations:
http://grove.ufl.edu/~fnaja/files/cpm00106.htm
Also see: CET 445 - Construction Planning and Scheduling, from Old
Dominion University:
http://www.odu.edu/webroot/instr/et/cconsidi.nsf/pages/cet445lecture1
Additional information and illustrations are available in a document
called "Project Management" hosted by Monash University.
See pages 5-6 for the differences between "precedence" and "arrow"
diagrams.
See page 16 for a Gantt chart.
http://www.gscit.monash.edu.au/~dengs/teaching/GCO2802/week5/lecture5-4up.pdf
(PDF format; Adobe Acrobat Reader is
required http://www.adobe.com/products/acrobat/readstep2.html )
search strategy: "gantt chart", "network diagram", precedence, arrow,
node, pert, project
I hope this helps. If anything is unclear, please use the "request
clarification" feature. Thanks. |
