need help for critical path analysis in java

[Divya Gehlot]

Hi,
I need to work on crtical path anlysis for project management.Can any one suggest me how the algorithm work in java 5.

[Gabriel Claramunt]

Do you have the algorithm description?

[Divya Gehlot]

Hi,
Critical Path for Project Management I need to implement for your refrence link Critical Path
even I dont have any idea regarding that but asked me to implement to that.
that why I posted my question in this forum please help me.

[Gabriel Claramunt]

If I recall correctly, you start with a list of tasks, their dependencies and duration, a project start date and a project end date.
You need to create a graph with the task dependencies.
Starting from the first task, traverse the graph calculating the earliest start date/end date for each one (the earliest start date for a task is the max earliest end date of its dependencies). Same for the latest start/end date, you traverse the graph "backwards" from the final task calculating the latest start/end date.
The critical path are the list of tasks whose earliest start/end date is the same as their latest start/end date.
Implementing the algorithm is not difficult but is not trivial either.
You need to create a suitable data structure and methods to construct the graph, traverse it updating the dates, and get the critical path.

[C.R.Muthukumar]

Originally posted by Divya Gehlot:
Hi,
I need to work on crtical path anlysis for project management.Can any one suggest me how the algorithm work in java 5.

Hello RanchHand
Pl find out if the shotestpath finding method, by making use of matrices
under the Dijikstra's Algorithm can be made in java from the C++ program(given below)
and if so the summary of the algorithm goes like this.In real life we are required to find the shotest path between two cities.For an airliner would be interested in finding the most economical route between any two cities in a given network of cities.This algorithm to find such a path was first propsed by E.W.Dijikstra
the program for sames in c++ is

 
  include <iostream.h>
 
const int INF = 9999 ;
 
int main( )
{
int arr[4][4] ;
int cost[4][4] = {
7, 5, 0, 0,
7, 0, 0, 2,
0, 3, 0, 0,
4, 0, 1, 0
} ;
int i, j, k, n = 4 ;
 
for ( i = 0 ; i < n ; i++ )
{
for ( j = 0; j < n ; j++ )
{
if ( cost[i][j] == 0 )
arr[i][j] = INF ;
else
arr[i][j] = cost[i][j] ;
}
}
 
cout << "Adjacency matrix of cost of edges:\n" ;
 
for ( i = 0 ; i < n ; i++ )
{
for ( j = 0; j < n ; j++ )
cout << arr[i][j] << "\t" ;
cout << "\n" ;
}
 
for ( k = 0 ; k < n ; k++ )
{
for ( i = 0 ; i < n ; i++ )
{
for ( j = 0 ; j < n ; j++ )
{
if ( arr[i][j] > arr[i][k] + arr[k][j] )
arr[i][j] = arr[i][k] + arr[k][j];
}
}
}
 
cout << "Adjacency matrix of lowest cost between the vertices:\n" ;
for ( i = 0 ; i < n ; i++ )
{
for ( j = 0; j < n ; j++ )
cout << arr[i][j] << "\t" ;
cout << "\n" ;
}
}
 

BestWishes

[C.R.Muthukumar]

Originally posted by Divya Gehlot:
Hi,
I need to work on crtical path anlysis for project management.Can any one suggest me how the algorithm work in java 5.

Hello RanchHand
No sooner i finished describing a ShortestMethod,than the following addtional stuff popped up to my initialisation as continuity.So please make use of the same

    
CriticalPathMethod(CPM)
The iterative procedure of determining the critical path is as follows.
Step1.
List all the jobs and then draw arrow(network)diagram.Each job is indicated by an arrow with the direction of he arrow showing the sequence of jobs.The length of the arrows has no significance.The arrows are placed based on prdecessor,successor and concurrent relation with in the job.
Step2.
Indicate  the normal time( tij) for ach activity(i,j) above the arrow which is deterministic
Step3.
Calculthe earliest start time   and he earliest finish time for each event and write the earliest time Ei for each event i int the (box--------).Alsocalculate the latestfinish and lateststart time.From this we calculate the latest time Ljfor each event j and put in the (triangle)
Step4.
Tabulate the various times namelynormaltime,earliesttime and the latest time on the arrow diagram
Step5.
Detrmine the total float foreach activity by taking thedifference between the earliest start andthe latest  start time.
Step6.Identify thecritical activities and connect them with the beginning event and ending event in the network diagram by double line arrowsWhich gives the criticalPath.
Step7.
Calculate the total project duration
 
 Critical Path Method (An Example)
----------------------
 

 

Immediate
Activity ID#Activity DescriptionPredecessorsEstimated Time
1Needs Analysis-4 weeks
2Architect Plans110 weeks
3Equipment Selection22 weeks
4Building Permits and Zoning24 weeks
5Vendor ID & Equipment Order33 weeks
6Construction516 weeks
7Interior Finish64 weeks
8Installation and Setup71 week
 

"Early start, early finish, late start, and late finish times in the table below came directly from exhibit 8.19 in"
the text.  The slack value for each activity was computed by subtracting the early start from the late start.
 

Activity ID#Activity DescriptionESEFLSLFSlack
1Needs Analysis04040
2Architect Plans4144140Input values with red background 
3Equipment Selection141614160can be changed to perform 
4Building Permits and Zoning141815191"""What if?"" analysis."
5Vendor ID & Equipment Order161916190
6Construction193519350
7Interior Finish353935390
8Installation and Setup394039400
 
The critical path is identified by the path of activities with zero slack. 

Now I am sure you would get to know the method of clearing your project in Java
BestWishes

[C.R.Muthukumar]

Originally posted by C.R.Muthukumar Muthukumar:


Hello RanchHand
No sooner i finished describing a ShortestMethod,than the following addtional stuff popped up to my initialisation as continuity.So please make use of the same

    
CriticalPathMethod(CPM)
The iterative procedure of determining the critical path is as follows.
Step1.
List all the jobs and then draw arrow(network)diagram.Each job is indicated by an arrow with the direction of he arrow showing the sequence of jobs.The length of the arrows has no significance.The arrows are placed based on prdecessor,successor and concurrent relation with in the job.
Step2.
Indicate  the normal time( tij) for ach activity(i,j) above the arrow which is deterministic
Step3.
Calculthe earliest start time   and he earliest finish time for each event and write the earliest time Ei for each event i int the (box--------).Alsocalculate the latestfinish and lateststart time.From this we calculate the latest time Ljfor each event j and put in the (triangle)
Step4.
Tabulate the various times namelynormaltime,earliesttime and the latest time on the arrow diagram
Step5.
Detrmine the total float foreach activity by taking thedifference between the earliest start andthe latest  start time.
Step6.Identify thecritical activities and connect them with the beginning event and ending event in the network diagram by double line arrowsWhich gives the criticalPath.
Step7.
Calculate the total project duration
 
 Critical Path Method (An Example)
----------------------
 

 
 
Immediate
Activity ID#Activity DescriptionPredecessorsEstimated Time
1Needs Analysis-4 weeks
2Architect Plans110 weeks
3Equipment Selection22 weeks
4Building Permits and Zoning24 weeks
5Vendor ID & Equipment Order33 weeks
6Construction516 weeks
7Interior Finish64 weeks
8Installation and Setup71 week
 
 
"Early start, early finish, late start, and late finish times in the table below came directly from exhibit 8.19 in"
the text.  The slack value for each activity was computed by subtracting the early start from the late start.
 
 
Activity ID#Activity DescriptionESEFLSLFSlack
1Needs Analysis04040
2Architect Plans4144140Input values with red background 
3Equipment Selection141614160can be changed to perform 
4Building Permits and Zoning141815191"""What if?"" analysis."
5Vendor ID & Equipment Order161916190
6Construction193519350
7Interior Finish353935390
8Installation and Setup394039400
 
The critical path is identified by the path of activities with zero slack. 

Now I am sure you would get to know the method of clearing your project in Java
BestWishes

   
Some more useful informations on the same topics is appended below 
 
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=windows-1252">
<META NAME="Generator" CONTENT="Microsoft Word 97">
<TITLE>Chapter 12</TITLE>
</HEAD>
<BODY>
 
<OL>
 
<P ALIGN="JUSTIFY"><LI>CPM is:</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Critical Project Management</LI></P>
<P ALIGN="JUSTIFY"><LI>Critical Path Management </LI></P>
<P ALIGN="JUSTIFY"><LI>Critical Path Method</LI></P>
<P ALIGN="JUSTIFY"><LI>Crash Project Method</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Which of these is not correct?</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>PERT is probabilistic in nature.</LI></P>
<P ALIGN="JUSTIFY"><LI>CPM is deterministic in nature.</LI></P>
<P ALIGN="JUSTIFY"><LI>CPM is event-oriented.</LI></P>
<P ALIGN="JUSTIFY"><LI>CPM and PERT use similar terminology, but were developed independently.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Mark the wrong statement:  </LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>A project is a set of activities, which can be performed in a certain logical sequence.</LI></P>
<P ALIGN="JUSTIFY"><LI>A network is a graphic portrayal of interdependency relationships among the activities of a project.</LI></P>
<P ALIGN="JUSTIFY"><LI>An arrow representing an activity can have any length and shape.</LI></P>
<P ALIGN="JUSTIFY"><LI>An activity cannot be represented by more than one arrow but an arrow can represent one or more activities.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Point out what is not required. </LI></P></OL>
 
<P ALIGN="JUSTIFY">While considering precedence relationships,</P>
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>all the predecessor(s) of an activity should be focussed on.</LI></P>
<P ALIGN="JUSTIFY"><LI>only immediate predecessor(s) should be focussed on.</LI></P>
<P ALIGN="JUSTIFY"><LI>redundant predecessors should be dropped.</LI></P>
<P ALIGN="JUSTIFY"><LI>care must be taken that there is no logical fault it as may result in formation of a loop.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Mark the correct statement:  </LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>The head event of an activity also represents tail event of its predecessor activity.</LI></P>
<P ALIGN="JUSTIFY"><LI>Nodes should be numbered in such a way that, for every activity, the initial node bears a lower number while final node bears a higher number.</LI></P>
<P ALIGN="JUSTIFY"><LI>The event marking start of an activity is called head event and the event marking the end is termed as tail-event.</LI></P>
<P ALIGN="JUSTIFY"><LI>In drawing a network, it may happen that A precedes B, B precedes C and C precedes A.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Which of the following is not a rule of network construction?</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Each defined activity is represented by one and only one arrow.</LI></P>
<P ALIGN="JUSTIFY"><LI>A network should have only one initial and one terminal node.</LI></P>
<P ALIGN="JUSTIFY"><LI>Identical initial and final nodes can be used to identify two activities.</LI></P>
<P ALIGN="JUSTIFY"><LI>Only as few dummy activities should be included as may be warranted.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Mark the wrong statement:</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Forward pass calculations yield the earliest and latest start and finish times of various activities.</LI></P>
<P ALIGN="JUSTIFY"><LI>The difference between latest and earliest finish times of an activity is its total float.</LI></P>
<P ALIGN="JUSTIFY"><LI>Free float of an activity cannot exceed its total float.</LI></P>
<P ALIGN="JUSTIFY"><LI>Determination of earliest and latest start time of various activities of a project is useful for proper planning of their execution.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>It is known that in a project, an activity 4-6 has duration of 6 days and total float of 3 days. The <I>E</I> and <I>L</I> times at node 4 are 8 and 11 respectively while at node 6, both are equal to 17. Which of the following is not a true statement about 4-6?</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Its free float is 3 days.</LI></P>
<P ALIGN="JUSTIFY"><LI>Its independent float is 0.</LI></P>
<P ALIGN="JUSTIFY"><LI>It is a critical activity.</LI></P>
<P ALIGN="JUSTIFY"><LI>The ES of this activity is 8.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Mark the wrong statement:  </LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>All activities on a critical path are critical activities.</LI></P>
<P ALIGN="JUSTIFY"><LI>A project network may have none, one or more critical paths.</LI></P>
<P ALIGN="JUSTIFY"><LI>A delay in a critical activity surely delays the completion of project.</LI></P>
<P ALIGN="JUSTIFY"><LI>Each critical activity has identical earliest and latest start times.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Pick the wrong relationship:</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Interfering Float = Total Float � Free Float</LI></P>
<P ALIGN="JUSTIFY"><LI>Total Float = Free Float + Independent Float</LI></P>
<P ALIGN="JUSTIFY"><LI>Total Float <FONT FACE="Symbol">³</FONT>
 Free Float <FONT FACE="Symbol">³</FONT>
 Independent Float</LI></P>
<P ALIGN="JUSTIFY"><LI>Free Float = Total Float � Head Event Slack</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Which of the following is not correct in respect of PERT calculations?</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Expected time of an activity is a weighted average of three time estimates, <I>a, m</I>, and <I>b</I> with respective weights of 1, 4 and 1.</LI></P>
<P ALIGN="JUSTIFY"><LI>The completion time of an activity is assumed to follow normal distribution.</LI></P>
<P ALIGN="JUSTIFY"><LI>The standard deviation of activity completion time is one-sixth of the excess of pessimistic over optimistic time.</LI></P>
<P ALIGN="JUSTIFY"><LI>The sum total of variances of critical activity times gives the variance of the overall project completion time.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Given, expected duration of project = 47 days, variance = 9 days<SUP><FONT FACE="Times New (W1),Times New Roman">2</SUP></FONT>. What is the probability of not completing the project in 50 days?</LI></P></OL>
<DIR>
 
<P ALIGN="JUSTIFY">Z       : 0.33	1.00	</P>
<P ALIGN="JUSTIFY">Area  : 0.1293	0.3413</P></DIR>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>0.6293</LI></P>
<P ALIGN="JUSTIFY"><LI>0.8413</LI></P>
<P ALIGN="JUSTIFY"><LI>0.1587</LI></P>
<P ALIGN="JUSTIFY"><LI>0.3707</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>In the Question 12 above, what is the probability of completing the project within 3 days more or less than the expected time?</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>0.5000</LI></P>
<P ALIGN="JUSTIFY"><LI>0.6826</LI></P>
<P ALIGN="JUSTIFY"><LI>0.2586</LI></P>
<P ALIGN="JUSTIFY"><LI>0.3174</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Which of the following is not true about crashing?</LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>Always focus on critical path and choose between critical activities only.</LI></P>
<P ALIGN="JUSTIFY"><LI>Crashing cost per day = (Crash cost � Normal cost)/(Normal time � Crash time).</LI></P>
<P ALIGN="JUSTIFY"><LI>Of all activities of the project, choose the activity with least crashing cost.</LI></P>
<P ALIGN="JUSTIFY"><LI>If there are multiple critical paths, crash them all.</LI></P></OL>
 
<P ALIGN="JUSTIFY"></P>
<OL>
 
<P ALIGN="JUSTIFY"><LI>Mark the wrong statement: </LI></P></OL>
 
<OL TYPE="a">
 
<P ALIGN="JUSTIFY"><LI>An event, which represents the initiation of more than one activity, is called the burst event.</LI></P>
<P ALIGN="JUSTIFY"><LI>The longest path of a given project gives the maximum duration while its shortest path indicates shortest duration.</LI></P>
<P ALIGN="JUSTIFY"><LI>The resource allocation programmes aim to allocate the given resources in a manner that the project completes in minimum time.</LI></P>
<P ALIGN="JUSTIFY"><LI>A non-critical activity may or may not have any free float.</LI></P></OL>
 
</BODY>
</HTML>
 

Hopefully this suffices for cpm project.Thanks

[Divya Gehlot]

Hi everyone,
Thanks for helping me.