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pert and cpm
« on: September 27, 2011, 05:00:49 PM »
Constraints: Restrictions set on the start or finish date of a task. You can specify that a task must start on or finish no later than a particular date. Constraints can be flexible (not tied to a specific date) or inflexible (tied to a specific date)

    * Flexible constraints such as As Soon As Possible (ASAP) and As Late As Possible (ALAP) do not have specific dates associated with them. Setting these constraints allows you to start tasks as early as possible or as late as possible with the task ending before the project finish, given other constraints and task dependencies in the schedule.
    * Inflexible constraints such as Must Start On (MSO) and Must Finish On (MFO) require an associated date, which controls the start or finish date of the task. These constraints are useful when you need to make your schedule take into account external factors, such as the availability of equipment or resources, deadlines, contract milestones, and start and finish dates.


Crashing: Shifting resources to reduce slack time so the critical path is as short as possible. Crashing always raises project costs and is typically disruptive a project should be crashed with caution. The goal of crashing a project is to reduce the duration as much as possible regardless of cost.  It is the opposite of relaxing a project.


Critical Path: The longest time path through the task network. The series of tasks (or even a single task) that dictates the calculated finish date of the project (That is, when the last task in the critical path is completed, the project is completed) The "longest" path (in terms of time) to the completion of a project. If shortened, it would shorten the time it takes to complete the project. Activities off the critical path would not affect completion time even if they were done more quickly.


Critical Path Method (CPM): A Project Management technique invented by American industry in 1958 as a means of controlling costs and schedules.  CPM is based on identifying and managing a path of critical activities that determine the project duration.  CPM theory is based on the concept that preceding tasks, not probability, determine the course of a project. CPM is frequently used with PERT.


Dependencies: Links between project tasks.  There are 3 types of dependencies:

    * Causal, where 1 task must be completed before another can begin (have to bake bread before you can make a sandwich)critical path schedules are based only on causal dependencies
    * Resource, where a task is limited by availability of resources (more bread can be baked by 2 bakers, but only 1 is available)
    * Discretionary, optional task sequence preferences that, though not required, may reflect organizational preferences


Dummy activity: An imaginary activity with no duration, used to show either an indirect relationship between 2 tasks or to clarify the identities of the tasks.

    * In CPM, each activity must be uniquely defined by its beginning and ending point. When two activities begin and end at the same time, a dummy activity (an activity which begins and ends at the same time) is inserted into the model to distinguish the two activities.

Duration: The time it takes for an activity to be completed, given the planned amount of material, labor and equipment.

Effort: The amount (not duration) of work required to complete a task. Duration may decrease by adding resources but the effort required will remain the same.


        I know its Diffcult so to reduce the diffculuty i had put the Shortcut method of the practical question here and theory you have to do on your own or some one put it out here on techshristi.

 For more Material


Milestone: A significant task which represents a key accomplishment within the project. Typically requires special attention and control.


Network Diagram: A wire diagram, also known as a PERT network diagram.  A diagram that shows tasks and their relationships; it is limited because it shows only task relationships. Its key strength is easy-to-read task relationships.


                    Sample Network Diagram



PERT:  (Program Evaluation and  Review Technique) A Project Management technique invented by (for) the U.S. Navy in 1958 as a means of projecting task and project completion and organizing complex sequences of tasks. PERT is based on the probability of an event occurring at a specified time. When used with CPM, it is the most commonly used Project Management methodology.


Project Management:  A management philosophy that says that efficient management will yield effective results. Specifically, efficient management of resources and constraints to perform tasks in order to achieve a desired result.

    * Project Management seeks answers to 2 key questions in order to craft effective project plans:
          o What tasks are necessary to do this project?
          o How long will it take to do those tasks?
    * Based on the answer to those 2 questions, PM answers 4 basic questions asked by most:
          o How long will this project take?
          o What will it take to do this project?
          o Can it be completed sooner?
          o How likely is it that it will be done on time?


Relaxation: The method that is the opposite of crashing a project. Relaxation is used to lower costs while extending the duration of the project. A typical use of this method is when a project may be relaxed if its resources are need on higher priority projects. This method involves deliberately lengthening the duration of the project with the specific aim of lowering costs as much as possible.


Resources: Time, money, people, equipment and other supplies are generally accepted as resources for planning and executing a project.


Scope: A specific definition of what the project does and does not entail. A well researched and coordinated scope of work is critical to managing expectations of customers and workers alike.


Slack Time: The amount of time a task can be delayed before the project finish date is delayed. Total slack can be positive or negative. If total slack is a positive it indicates the amount of time that the task can be delayed without delaying the project finish date. If negative, it indicates the amount of time that must be saved so that the project finish date is not delayed. (Slack time is also known as float time)

    * Total Slack = Latest Start - Earliest Start.
    * By default and by definition, a task with 0 slack is considered a critical task. If a critical task is delayed, the project finish date is also delayed.
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pert and cpm
« on: September 27, 2011, 05:00:49 PM »

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