Sunday, August 2, 2009

GANTT CHART

A Gantt chart is a type of bar chart that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project. Some 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 as shown here.
Although now regarded as a common charting technique, Gantt charts were considered revolutionary when they were introduced. In recognition of Henry Gantt's contributions, the Henry Laurence Gantt Medal is awarded for distinguished achievement in management and in community service. This chart is used also in Information Technology to represent data that has been collected.
Advantages and limitations
Gantt charts have become a common technique for representing the phases and activities of a project work breakdown structure (WBS), so they can be understood by a wide audience.
A common error made by those who equate Gantt chart design with project design is that they attempt to define the project work breakdown structure at the same time that they define schedule activities. This practice makes it very difficult to follow the 100% Rule. Instead the WBS should be fully defined to follow the 100% Rule, then the project schedule can be designed.[citation needed]
Although a Gantt chart is useful and valuable for small projects that fit on a single sheet or screen, they can become quite unwieldy for projects with more than about 30 activities. Larger Gantt charts may not be suitable for most computer displays. A related criticism is that Gantt charts communicate relatively little information per unit area of display. That is, projects are often considerably more complex than can be communicated effectively with a Gantt chart.
Gantt charts only represent part of the triple constraints of projects, because they focus primarily on schedule management. Moreover, Gantt charts do not represent the size of a project or the relative size of work elements, therefore the magnitude of a behind-schedule condition is easily miscommunicated. If two projects are the same number of days behind schedule, the larger project has a larger impact on resource utilization, yet the Gantt does not represent this difference.
Although project management software can show schedule dependencies as lines between activities, displaying a large number of dependencies may result in a cluttered or unreadable chart.
Because the horizontal bars of a Gantt chart have a fixed height, they can misrepresent the time-phased workload (resource requirements) of a project. In the example shown in this article, Activities E and G appear to be the same size, but in reality they may be orders of magnitude different. A related criticism is that all activities of a Gantt chart show planned workload as constant. In practice, many activities (especially summary elements) have front-loaded or back-loaded work plans, so a Gantt chart with percent-complete shading may actually miscommunicate the true schedule performance status.
The Program (or Project) Evaluation and Review Technique (PERT)

Commonly abbreviated PERT, is a model for project management designed to analyze and represent the tasks involved in completing a given project.
PERT is a method to analyze the involved tasks in completing a given project, especially the time needed to complete each task, and identifying the minimum time needed to complete the total project.

PERT was developed primarily to simplify the planning and scheduling of large and complex projects. It was able to incorporate uncertainty by making it possible to schedule a project while not knowing precisely the details and durations of all the activities. It is more of an event-oriented technique rather than start- and completion-oriented, and is used more in projects where time, rather than cost, is the major factor. It is applied to very large-scale, one-time, complex, non-routine infrastructure and Research and Development projects.
This project model was the first of its kind, a revival for scientific management, founded by Frederick Taylor "Taylorism" and later refined by Henry Ford "Fordism". DuPont corporation's critical path method was invented at roughly the same time as PERT.
Conventions
• A PERT chart is a tool that facilitates decision making; The first draft of a PERT chart will number its events sequentially in 10s (10, 20, 30, etc.) to allow the later insertion of additional events.
• Two consecutive events in a PERT chart are linked by activities, which are conventionally represented as arrows in the diagram above.
• The events are presented in a logical sequence and no activity can commence until its immediately preceding event is completed.
• The planner decides which milestones should be PERT events and also decides their “proper” sequence.
• A PERT chart may have multiple pages with many sub-tasks.
Pert is valuable to manage where multiple task are going simultaneously to reduce the redundancy

Work Breakdown Structure (WBS)

Refers to a portion of a total project management plan that is used by the project management team to organize a project into manageable objectives and create a blueprint by which the steps leading to the completion of a project are obtained.
The Work Breakdown Structure can be thought of like an outline of the project and like an outline, becomes more detailed under the subheadings or work packages. The whole project is defined by the Work Breakdown Structure, with the work packages fitting together at the completion of the project to complete the whole.
The work packages are individual steps or portions of the task that must be completed in order to achieve the project management goal. It allows for several different teams to work simultaneously on seperate components of a project. This outline applies to any project where a good or service must be presented to the client in timely manner. These goods or services are called the deliverables, and can be either internal or external. Other terms that are related are work package, control account, contract work breakdown structure, and project summary work breakdown structure.
The Work Breakdown Structure Dictionary is a useful resource for project management, and should be consulted for relevant information on each component of the work breakdown structure (WBS). The WBS dictionary includes entries for each WBS component that briefly defines the scope or statement of the work, defines deliverables, contains a list of associated activities, and provides a list of recognized milestones to gage progress.
Project management should also consult the Work Breakdown Structure Dictionary for other information such as:
- Identifying which organization is responsible for the specific work component.
- Scheduled start and end dates.
- Required resources.
- Estimated cost of project.
- Charge numbers.
- Contract information, details & requirements.
- Quality control protocol, requirements & standards.
- Technical information necessary for proper performance of work.
The Work Breakdown Structure Dictionary is an essential information resource for project management. It should be consulted before commencing any work component in order to insure that proper standards, procedures, and quality control measures are being followed. Due to ever changing circumstances, the Work Breakdown Structure Dictionary is under constant revision. Therefore, frequent review of its contents will assure proper project management.
This term is defined in the 3rd edition of the PMBOK but not in the 4th.

The S-Curve

SCurve for Microsoft Project is used to plot S curves for a single, master project or selected activities. Three curves are presented, baseline, actual and schedule for a given MSProject. SCurve can help you track your MSProjects visually using an S-Curve graph. Progress and schedule are shown against base line so you can see where you are now compared to where you said you would be. Version 0.1.20 may include unspecified updates, enhancements, or bug fixes.
The S-Curve emerged as a mathematical model and was afterwards applied to a variety of fields including physics, biology and economics. It describes for example the development of the embryo, the diffusion of viruses, the utility gained by people as the number of consumption choices increases, and so on.