start a task a specified time before another task

[Adam]

Hi,

I can set a "must start on" or a "start no earlier than" constraint to
require a task to start by a certain date, but how do I set a constraint to
make a task start a certain amount of time before another task? In effect,
it's like I want to schedule backwards - for a single task, not the whole
project.

Thanks

 

[John]

Hi,

I can set a "must start on" or a "start no earlier than" constraint to
require a task to start by a certain date, but how do I set a constraint to
make a task start a certain amount of time before another task? In effect,
it's like I want to schedule backwards - for a single task, not the whole
project.

Thanks

Adam,
Take at look at the start-to-start constraint type. Use a lead to set
the amount of time the first task starts before the next task. For
example, let's say you have Task "a" and it's ID is 5. You want Task "b"
to start 5 days after task "a" starts. Set the predecessor for Task "b"
as: 5ss+5d.

You can also set a relative lead time. For example, let's say you want
Task "b" to start halfway through the duration time of Task "a". Set the
predecessor for Task "b" as: 5ss+50%. Note that if the duration of Task
"a" increases, the delay start time of Task "b" also shifts, unless of
course Task "b" has already started, then the predecessor is null and
void.

Hope this helps.
John
Project MVP