Project Management

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.

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 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 utiization, yet the Gantt does not represent this difference.




WORK BREAKDOWN STRUCTURE (WBS)

A tool used to define and group a project's discrete work elements (or tasks) in a away that helps organize and define the total work scope of the project.

A work breakdown structure element may be a product, data, a service, or any combination. A WBS also provides the necessary framework for detailed cost estimating and control along with providing guidance for schedule development and control. Additionally the WBS is a dynamic tool and can be revised and updated as needed by the project manager.

The work BREakdown Structure is a tree structure, which shows a subdivision of effort required to achieve an objective; for example a program, project, and contract. In a project or contract, the WBS is developed by starting with:

• the end objective and
• successively subdividing it into manageable components
• in terms of size, duration, and responsibility (e.g., systems, subsystems, components, tasks, subtasks, and work packages)
• which include all steps necessary to achieve the objective
  

S-CURVE

Important project management tool. They allow the progress of a project to be tracked visually over time, and form a historical record of what has happened to date. Analyses of S-Curves allow project managers to quickly identify project growth, slippage, and potential problems that could adversely impact the project if no remedial action is taken.

How is an S-Curve Generated?

To generate a Baseline S-Curve, a Baseline Schedule is required. The Baselline Schedules should contain the following information for each task:

• Baseline Start Date, Finish Date
• Baseline Man Hours and/or Costs
  

To generate Actual and Target S-Curves, a Production Schedule is required. The production schedules should contain the following information for each task:

• Actual Start Date, Finish Date
• Actual Man Hours and/or Costs
• Actual Percentage Complete
  

PERT/CPM

The final network models we discuss are the PERT and CPM models for project scheduling. The successful management of large projects, be the construction, transportation, financial, or what-have-you, relies on careful scheduling and coordinating of various tasks. CPM (Critical Path Method) and PERT (Project Evaluation and Review Technique) attempt to analyze project scheduling This allows for better control and evaluation of the project.

CPM and PERT have been used in a wide variety of projects , from designing and producing computers to scheduling a complex surgery. The essential ideas behind these techniques are quite straightforward

CPM uses a project network to portray graphically the relationships among the tasks in a project.

Each arc of the project represents a task, or activity. This is the activity on arc(AOA) representation. Each node represents an event. The direction of the arcs gives the sequences in which activities must be achieved. An event must precede the beginning of succesive activities, and an event occurs only when all the activities immediately preceding it occur.

The Program Evaluation and Review TEchnique (PERT) is a network model that allows for ramdomnes in activity completion times. PERT originally was an activity on arc network, in which the activities are represented on the lines and milestones on the nodes. OVer time, some people began to use PERT as an activity on node network.