Goodluck O-10 IT-Appers

[papertissue]

As long as it's readable, it should be good. However, you really don't need to write that much to get full marks.
Quality over quantity

[nacho]

IT is my worst subject, even though it's my only year 12
gl for tomorrow guys, epic study sesh till 12:30.

[papertissue]

It's my only year 12, too
What happens after 12:30? Meditation, nap, COD?
I'll have to study til 3pm or I'll feel guilty

[nacho]

12:30 AM i mean, so yea, nap.
After that, wake up 8:30 (8 hours sleep)
normal routine, study till 1pm maybe, then for 90 minutes, chillax, keep my mind off the exam
Crap, ONE LAST QUESTION.
VCAA 2009 (78/90 )
Question 20 from MC.
Question 20
Task X has 20 days duration and Task Y has 15 days duration. Task X is a predecessor of Task Y. Task Y cannot
start until 10 days after Task X has finished.
If Tasks X and Y are on the critical path, the 10 days of delay for Task Y is called
A. lag.
B. lead.
C. start to start time out.
D. finish to finish time out.

I put B, answers says A.
I'm almost positive it's still B?
The 10 days leading up to task Y (as it must wait 10 days before it can start) is lead time?
10 days of delay for task Y Where'd they even get this from, are they proposing task Y can go over board by 10 days without affecting the critical path?
Something's wrong, i don't understand...

[ttn]

Question 20
Task X has 20 days duration and Task Y has 15 days duration. Task X is a predecessor of Task Y. Task Y cannot
start until 10 days after Task X has finished.
If Tasks X and Y are on the critical path, the 10 days of delay for Task Y is called
A. lag.
B. lead.
C. start to start time out.
D. finish to finish time out

I put B, answers says A.
I'm almost positive it's still B?
The 10 days leading up to task Y (as it must wait 10 days before it can start) is lead time?
10 days of delay for task Y Where'd they even get this from, are they proposing task Y can go over board by 10 days without affecting the critical path?
Something's wrong, i don't understand...

lag time refers to time between tasks.

[nacho]

oh that's right.
I always thought the definiton was the amount of time a task may run overboard without affecting the critical path?

[ttn]

lol that's slack time.

[nacho]

i thought lag time and slack time were the same thing?

[Plan-B]

Yeah I thought so too..
Definition page 30 Potts, "Lag time, or slack time, relates to the amount of time there is between tasks. The lag time for an event is the amount of time by which the event can run over time without delaying the project".

Mark Kelly has a slight variation:
http://vceit.com/ganttpert/projmanterms.htm
But they both essentially apply to the same thing I guess.

Lead time is the time leading up too or before a task. In the case of that question, it would be 30 days lead time for Task Y.

[papertissue]

The Potts definition is pretty horrible :|

Would this definition be okay? "Lag time is the amount of time a task must wait even though its predecessor has finished. (e.g. drying concrete)"

[nacho]

Great, now im confused LOL so bad.
This is what i gather now.
Lag team : Time inbetween tasks
Slack time: DIFFERENT FROM Lag time, time a task can go overtime without affecting the end date of the project
Lead time: Time leading up to a task,
Eg task A = 5 Days
    task B = 2 days
Task C canonly start after both task  A and B are finished plus two days, so:

Task C has a lead time of 7 days.
Task B has a slack time of 2 days.
Task C has a lag time of 2 days?

[ttn]

They said task Y cannot start until 10 days after task X has finished. So it's definitely not slack, as that would  instead mean Task X has an extra 10 days to finish or Task Y wouldn't have to wait 10 days after task X.

And lead time refers to the amount of time leading up to the task from the start of the project.

[nacho]

Is my example correct?

[ttn]

Eg task A = 5 Days
    task B = 2 days
Task C canonly start after both task  A and B are finished plus two days, so:

Task C has a lead time of 5 days.
Task B has a slack time of 3?? days.
Task C has a lag time of 3 days from task B

Task A and B start at same time right? If so, thats what I think it is.

[Plan-B]

Umm and assuming task a and b start at the same time,
I think
Task C has 5 days lead time (By definition)
Task B has 3 days slack time (Task B can run over 3 days, meaning it finishes at the same time as Task A, thus not effecting the deadline)
Task B also has 3 days lag time (If the project runs accordingly, Task C begins immediately after Task A (because longest task), and Task A is 3 days longer then Task B, meaning the lag time is also 3 days)

Therefore, Slack Time = Lag Time?

Remember, lag time is the amount of time a task can run over time without affecting the critical path. Task B can run over time, not Task C

Thats my understanding of it, but I may be wrong.