3.3.4 critical path analysis Flashcards
define critical path analysis
a management tool which helps a business identify how long a project will take and what the critical tasks in the project are
uses of CPA
can be used to schedule a building project.
can be used to launch a new product onto a market.
installation of new technology
benefits of using cpa
stakeholders will be able to see total time frame for a project.
reduces capital tied up in resources waiting to be used.
useful for businesses in markets where speed is important
how a cpa diagram works
starts with a list of tasks which state how long they will take and the order they should be carried out.
start of the diagram = first day of project shown in a circle.
lines between the circles show each task.
next circle adds the days of the previous task on
how to calculate the est
add from the left the duration times.
node 1 = start day is 0.
node 2 = have to add on 3 days work for task A.
node 4 = we add 12 the duration of the next activity.
node 6 = take the longest days value where two nodes meet.
node 7 = add 4 days duration.
node 8 = add 6 days duration.
node 9 = add 4 days duration.
gets the total time for the projects
how to calculate the lft
subtract from the right duration times.
node 9 = completion day is day 58.
node 8 = subtract 4 days duration.
node 7 = subtract 6 days duration.
node 6 = subtract 4 days duration.
node 5 = subtract 12 days duration.
node 4 = subtract 12 days duration.
node 3 = subtract 36 days duration.
node 2 = two lft to choose from, select the lowest lft
how to calculate float time
when nodes are the same top and bottom there is no spare time so these tasks are critical.
if these tasks are delayed they will delay the whole project.
we need to know where is some float time.
lft - duration - est
limitations of cpa
all the data in the network is based on estimates and can quickly become inaccurate.
drawing up on a diagram is time consuming.
project may be simple and not require a diagram
