Create the Critical Path

Quick reference

• 00:04 We have taken our first pass at linking all of the tasks together using
• 00:08 the Predecessor column.
• 00:10 In the previous lesson, I pointed out that the Successor column fills in for
• 00:14 us automatically.
• 00:16 Now sometimes you'll see these blank lines here on the Successor column.
• 00:22 And that's bad, because that means some tasks aren't fully linked.
• 00:27 And you can see that here with this higher interior designer task.
• 00:32 If we look over here,
• 00:33 we can see that it is actually linking back to installing the house frame.
• 00:38 However, no other task is linking to it.
• 00:42 If we don't link all of the tasks together then we do not get the critical path.
• 00:48 What's important about the critical path is that if one task moves just even one
• 00:53 day, all of the other tasks could move out, pushing the project out one day.
• 00:59 So all critical tasks need to be identified and
• 01:03 accounted for and we can only do that by linking all of the tasks together.
• 01:09 If it is very clear to us which tasks to link together, we can just go through and
• 01:13 type that linkage immediately right here in the predecessor or successor column.
• 01:20 However, sometimes you want to identify these tasks in a number of different ways.
• 01:26 The way I like to do it is to use the network diagram.
• 01:29 And we access the network diagram by clicking the Tasks tab,
• 01:34 clicking the Pick List for Gantt Chart and choosing Network Diagram.
• 01:39 Now in the network diagram, I'm gonna scroll all the way to the left and
• 01:44 I'm gonna zoom all the way out.
• 01:47 I'm using the Zoom control on the bottom right hand side of the screen.
• 01:52 So what we can see here is the start of our project which is the My New House.
• 01:57 That's task line zero.
• 01:59 And remember, we do not need to link this task.
• 02:03 Now task line zero and any other summary task that we create is represented by
• 02:08 a parallelogram, which is essentially just sort of this shifted rectangle.
• 02:14 We don't need to link those ever, we shouldn't actually link those together.
• 02:18 So we're using the network diagram as to easily identify tasks
• 02:22 that don't have a linkage in the project, and actually there's a few of them.
• 02:27 So if we come over here and mouse over this task it says, hire interior designer.
• 02:33 Well, we need to link that task to something else.
• 02:36 Chances are, it gets linked to something close by.
• 02:40 So let's take a look at some of the other tasks around it.
• 02:44 Here's install roofing.
• 02:49 Here's install siding.
• 02:53 Here's install drywall.
• 02:57 And here's paint walls.
• 03:00 Well, I think the interior designer is gonna be painting those walls.
• 03:05 So what we're going to do is say that this task and this task are linked together.
• 03:13 We have another task up here that's not linked.
• 03:15 That's install plumbing.
• 03:16 If I come over here, we have install siding.
• 03:22 So we can install siding after install plumbing is done.
• 03:26 So again, we'll drag and drop the task there.
• 03:31 We have one more task that's not linked.
• 03:38 This is install furnishings.
• 03:41 Now here's an interesting one.
• 03:43 These furnishings are probably the same job as the interior designer.
• 03:48 So we can actually link one task to multiple tasks.
• 03:52 So here's the install interior designer.
• 03:55 I'm going to also link that task to it.
• 03:59 And finally,
• 04:00 I want to make sure that this is linked to another task throughout the critical path.
• 04:05 And by the way, all these red items,
• 04:09 these are all marked as critical path, because they're red.
• 04:14 So I'm gonna look at this, and this is install furnishings.
• 04:20 Here's build out kitchen.
• 04:23 Here's paint walls.
• 04:28 Here's add furniture.
• 04:31 I'll go ahead and associate the furnishings with the furniture.
• 04:38 Now, I'll go ahead back to the Gantt Chart by clicking the Task tab and
• 04:42 clicking Gantt Chart.
• 04:46 Now we've linked all of our tasks together.
• 04:51 Notice that some tasks are linked with a comma.
• 04:55 You can actually link multiple tasks to one single task.
• 05:00 So now install furnishings is linked to task 13 and 15.
• 05:06 Let's take a closer look at this install furnishings task with 13 and 15.
• 05:11 Notice on the Gantt chart we have arrows going up and down.
• 05:16 We have this because this Install Furnishings is not located
• 05:19 in the right place.
• 05:20 The interior designer's going to do that.
• 05:23 And they can't do that until after we've hired them.
• 05:26 So let's take line 14, click on the row, use your mouse to drag it under 15,
• 05:31 and now you can see the arrows are now flowing in our waterfall method.
• 05:36 So we’ve used the network diagram, now, to link the tasks.
• 05:39 And we’ve reviewed our Gantt chart to make sure we don’t have
• 05:43 tasks pointing up and down in it.
• 05:46 And we now have a full, critical path for our project.

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