Time Management Question

Submitted by henrypmp123 on Sat, 11/24/2012 - 15:14

From Exam Central


An activit has an ES of 3 days, LS of 13 days, EF of 9 days and LF of 19 days.


What is the duration of the activity?


A. 3


B. 6


C. 7


D. 10


Could someone kindly explain it? as i found some different calcution and thus result in wrong ans.


Thanks a lot !!!

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guptaab1

Sun, 11/25/2012 - 06:27

This question is incomplete. For us to calculate the duration of the activity, it is required to know whether the network diagram's 1st activity start's with day 0 or 1. If this is known then the activity duration can be calculated to be 6 or 7.

If the 1st activity starts with day 0 (formula : EF=ES+duration or LS=LF-duration) then activity duration is 6 and if it starts with day 1 activity duration is 7 (formula : EF=ES+duration-1 or LS=LF-duration+1).

However, if it all this question appears in the exam in the above manner, we are required to assume that 1st activity starts on day 0 and calculate the duration as 6 days.

 

Regards,

Amit

Sacramanto (not verified)

Sun, 11/25/2012 - 07:45

 The question in Rita by the way and the answer is 7 .

without giving any information more 

 

thanks 

henrypmp123

Tue, 11/27/2012 - 14:07

Rita ans is 7 but exam central is 6 (B)


i really confused

sspawar

Wed, 12/05/2012 - 13:34

PMI follows Zero method,

In this method

 ES or LS of questioned activity is a  finish date (EF or LF) of precedessor (passed) activity.

And thus work for this activity is starting on morning of 4th and ending at evening of 9th.

thus count on finger - 4, 5, 6,7, 8, 9, = 6days duration (9-3=6)

(thus for successor of questioned activity ES = will be written as 9 but in actual it will start by 10.)

------------------------------------------------------------------------------------------------------

The 1 method shows starting date (ES or LS)  same as on it starts, and finish date also the same .

in this case same date as written ES =3 will be taken in account hence count on finger = 3,4,5,6,7,8,9 = 7 days duration (9-3+1)

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Now what to do in PMP

  • There in exam almost 4 to 6 questions come on network diagram, only 1 or 2 such q will come  of this pattern (means on ES /LS/EF/LF)
  • there option either will be 6 or 7 . not both.
  • IF both options are there , then follow 0 method.

 

sspawar

Wed, 12/05/2012 - 10:14

    FORWARD Pass            
    PATH  --A-B-E = 10            
    PATH -- A-C-D-E = 19          
    HENCE CRITICAL PATH IS ACDE FIRST COMPLETE WITH CRITICAL PATH  
                   
  Zero Start Method            
    4 7   EF-ES=LF-LS=DURATION    
      B/3            
          16 19      
0 4         E/3      
  A/4                
                   
    4 11 11 16   ES EF  
      C/7   D/5   ACTIVITY/
DURATION		    
                 
              LS LF  
                   
  One StartMethod             
          EF-ES+1=LF-LS+1=DURATION    
    5 7            
      B/3            
          17 19      
1 4         E/3      
  A/4                
                   
    5 11 12 16        
      C/7   D/5        
                   
                   
                   
      BACKWARD Pass   Take first CRITICAL path  
    Zero Start Method          
      4 7   EF-ES=LF-LS=DURATION  
        B/3          
            16 19    
  0 4 13 16     E/3    
    A/4              
            16 19    
  0 4 4 11 11 16   ES EF
        C/7   D/5   ACTIVITY/
DURATION		  
                 
      4 11 11 16   LS LF
                   
    One StartMethod           
            EF-ES+1=LF-LS+1=DURATION  
      5 7          
        B/3          
            17 19    
  1 4 14 16     E/3    
    A/4              
            17 19    
  1 4 5 11 12 16      
        C/7   D/5      
                   
      5 11 12 16