Microsoft Project 2019: Linking Tasks and Dependencies

Welcome back to our course on Project 2019. In this section, we’re going to look at dependencies. As we’re doing that we’re going to add quite a bit more detail into this wedding plan.

Now you might be wondering what a dependency is. Well, a dependency reflects the fact that some things happening depend on other things happening.

The way in which they depend can be quite complex. In a very simplest type of dependency, we would say that one task cannot start until another task finishes.

We can have much more complex dependencies than that. In particular, one task may depend on many other tasks. 

Now let’s start looking at this. Let’s take a pretty straightforward dependency, to begin with. So let’s take a look at Task 6 and 7. Select wedding dress and Order dress. 

Now clearly, you’re not going to order the dress until you’ve selected it. As soon as you have selected it you might then want to order it.

If I want to record in my schedule that one. The task is dependent on another. The very simplest way of doing it, let me select this first task here. Task 6. I’m going to hold down my Control key and select Task 7.

I have both of those tasks selected currently. I’m then going to go up to the Task tab. In the Schedule group, there is a button just here. It looks like a chain-link button and it says Link the selected tasks.

You can see there! There is a shortcut key to Control plus F2. Let’s click that. You can link tasks so one can’t start until the other one has finished. This establishes the very simplest kind of dependency. 

Now if you look over on the Gantt Chart, you can see that we now have an arrow. It’s indicating the dependency whereby Task 6 must finish. You can see the little arrow there.

It comes out of Task 6 at the finish line essentially and points towards the start of Task 7. If I pull this divider here you’ll see that that reveals the Predecessors column.

You could see that now. For Task 7 in the Predecessors column, it now has the number six in there. In which states that Task 7 is dependent on Task 6 completing. 

Now let’s look at the duration of these tasks. So let’s go back to Select a wedding dress. This is obviously very difficult to be absolute about. But let’s suppose that the bride has decided. In order to select a wedding dress, it’s actually quite a long and complex process.

She’s probably going to need maybe a month or two. In order to be able to do that. Let’s assume that in terms of working days, weekday working days. Let’s call it eight weeks or 40 days in this case.

If I click on the wedding dress task and go to Duration. I’m just going to change this to 40 days. You can see immediately that the Gantt Chart updates to reflect that.

Now that’s all fine but in terms of ordering the dress that’s a reasonably quick task. Once you’ve made the selection you’re probably going to order that dress fairly quickly.

So that could be a matter of going into the store and filling in a form, committing to spend a certain amount of money, maybe paying the deposit on the dress. And we’ll talk about things like cost later on. And we’re really going to say that the order is going to be placed in a day.

So let’s change this Order dress and currently, we have an estimate in here of 1 day. Remember that’s what the question mark represents. It’s just an estimate currently. So I’m going to go in and change this from an estimate to a fixed duration.

I can do that in a couple of ways. I could go in and edit the cell. Or I could double click on the task to bring up the task information. Just take that tick out of estimated and click on OK.

Now, once the dress has been ordered, the measurements and fittings can start. There’ll be a sequence of these until the dress is finalized. Once again let’s assume that it’s going to take a total period of 40 days for all that to happen.

We can select Task 7 and we can select Task 8, Control key. We could create a dependency in exactly the same way we did before.

However, if I right-click on the selection if you look at the mini toolbar down here. You’ll see that it has a link button, so I can do the link that way.

And I can do the link before I establish the second duration. So let me double click on Task 8 and change its duration to Not estimated and 40 days. And there we are. And at the end of Task 8, we should have a wedding dress that fits. 

Let’s move on to Task 9. Select and order bridesmaid dresses. Now, this is not a task which is completely independent of the wedding dress. Because as I understand it. In general, the wedding dress would be selected first with a thought to what the bridesmaid’s dresses will be like.

But you certainly wouldn’t start selecting the bridesmaid dresses until you are certain about the wedding dress. In this case, say that the dependency is. We’ll select the wedding dress before we select and order bridesmaid’s dresses.

In reality, with a Select and order bridesmaids dresses. That’s probably going to be broken down into more subtasks underneath. But for the moment we’ll stick with what we have.

Let’s establish a link between Select wedding dress. Select and order bridesmaid’s dresses. So up to the Task Ribbon, and in the Schedule group. We’re going to click that Link the selected task button again.

And let’s change this duration. I’m going to double click on the task. We’re going to take the tick out of Estimated. And we’re going to say the duration is 60 days. You can see by looking at our schedule now this takes us towards the middle of July. 

You can also see on our schedule that Select wedding dress. Now has a number of tasks dependent on it. Of course, any task cannot only have several tasks depending on it. But it can depend on several tasks as well. 

Now let’s start to look at these dependencies in a little bit more detail.  

There is a dependency from Task 6 to Task 9. We just set that up. If I hover over the arrow that represents that dependency. There is a screen tip that comes up that gives me a summary of the dependency. It’s an FS, a Finish to Start dependency.

That means that the first task in the dependency, that is Select wedding dress must finish or F before Select and order bridesmaid’s dresses can start. And that is what the S is. And in fact, if I double click on that line I get a Task Dependency dialog where I could if I wanted to change that dependency. 

So it says from Select wedding dress to Select and order bridesmaid’s dresses there is a Finish to Start dependency with a lag of zero days. Now if I decided in this particular case that after the wedding dress was selected and at that point we were going to order it we could certainly start looking at selecting and ordering bridesmaid’s dresses.

But we needed to leave a gap of say five days for some reason and that would represent a lag of five days. So let’s do that. Let’s change the lag to five days just using those scroll buttons and click on OK. So now you’ll see that there is a five-day gap between the finish of Select wedding dress and the start of Select and order bridesmaid’s dresses. So that is what we call a lag.

And I could also have said that there is a lag of minus five days. So let’s take a look at that. I’m going to double click and I could take that back five days or to minus five days like so.

Now that is what we call a negative lag. And we often refer to it as a lead. We still have a finish to start a relationship but what the relationship now says is that the second task can start five days before the first task finishes.

So we can actually get started on selecting and ordering the bridesmaid dresses five days before we finish selecting the wedding dress. And again you can see that represented here on the Gantt Chart. There is an overlap between Selecting the wedding dress and Selecting and ordering the bridesmaid’s dresses.

Now I’m going to restore that to being a lag of zero days in a moment but first of all, I’d like you to look at the Predecessors column. If you look at Task 7, Order dress, it’s predecessor was six. Look at Task 8. Its predecessor was seven.

When all you see in the Predecessor column is a number that indicates a default finish to start a relationship with zero lag. If there’s more complexity to the dependency then you’ll see something such as you can see for Task 9. The dependency is on Task 6.

So it begins with a six. The FS basically says that it is a finish to start dependency, which is the default. But the reason it says that is because it then says minus five days. So that code tells you that Task 9 has a finish to start a relationship with Task 6, which means that six must finish before nine starts but there is a five-day lead. So in effect Task 9 can start five days before Task 6 finishes. 

And whenever there is anything other than a standard default finish to start a relationship, so if it’s any other type of relationship or if there is lag or lead you’ll see that coded into this Predecessors column.

So let me once again open up that dialog. So I’m going to double click and I’m going to change that lag back to zero days. But just before I click on OK let’s take a look at the other types of dependency.  

Now there are four types in total. Finish to Start which is the default as I mentioned. There is also Start to Start which means that the second task can start when the first one days. Of course, you can apply lag or lead to any of these.

The next one is Finish to Finish which means that the second task can only finish when the first task finishes. And then there is Start to Finish, which means that the second task can’t finish until the first task starts.

Now by far, the most common dependency is the Finish to Start but you are very likely to come across the others at some point. And in the next section or two, I’m going to show you one or two examples of these other types of dependency.

The next task I want to look at is the task of Making the guest list. Now making the guest list can be quite a long and controversial subject. I’m going to assume for a moment that it’s going to take maybe three to four weeks to try and make sure that everybody that should be invited is invited.

So let’s change this from 8 to 15 days. And again you can either click in the cell and change it up here or double click on the task. So I’m just going to put 15 and click the tick.

But let’s also say that once we’ve got some guests on the guest list who are definitely going to be invited we might start sending out the invitations pretty much straight away.

So for Task 13, Send out invitations, this would be a task that would pretty much run throughout the period of making the guest list. We may even wait to see what responses we get to some of the invitations.

So let’s extend Send out invitations to be a 20-day task. So this time I’m going to double click and I’m going to change that to 20 D and OK. And let’s say that this is going to start five days after Making the guest list starts. So once we’ve been working on the guest list for a week we’re going to start sending out the first batch of invitations and see what sort of responses we get. 

So let’s link these two. Up to the Task Ribbon and click our Link button. And I’m going to double click and set my task dependency. So this is going to be Start to Start and we’re going to put a five-day lag in there. 

Now we need to allow time for people to respond to invitations. As usual quite a controversial subject, how long you would like to give people to respond to an invitation, but probably a figure of something like two or three weeks.

So you’re going to start sending out invitations on a particular date and then over a period of time you’ll send out some more and you’ll start to get replies back. But in reality, you can’t really finalize the guest list until you’ve received all of the responses to the invitations.

So what I’m going to do is to create a link between Send out invitations and Finalize guest list. So I’ve created a link between those two and I’m going to put a lag of 15 days in. Instead of saying it’s a Finish to Start link I’m going to say that it’s a Finish to Finish link.

I’m also going to say that Finalize guest list is a five-day task. What you can see there is a situation where at some point before our deadline we’re going to start to finalize the guest list but we’re not actually going to be able to finish it until 15 days after we’ve sent out the last invitation.

Now, of course, the way that I’ve done it that was partly just to demonstrate these types of dependency but you’ll see from that also that when you’re setting up dependencies there are often a number of options to consider. And coming up with the right sort of dependency can sometimes involve quite a bit of thought and discussion.

So we’ve put quite a bit more detail into our plan now for the wedding. In the next section, we’re going to look at constraints and deadlines and we’re going to do a little bit more on dependencies as well. So please join me in the next section for that. 

Deborah Ashby

Deborah Ashby is a TAP Accredited IT Trainer, specializing in the design, delivery, and facilitation of Microsoft courses both online and in the classroom.She has over 11 years of IT Training Experience and 24 years in the IT Industry. To date, she's trained over 10,000 people in the UK and overseas at companies such as HMRC, the Metropolitan Police, Parliament, SKY, Microsoft, Kew Gardens, Norton Rose Fulbright LLP.She's a qualified MOS Master for 2010, 2013, and 2016 editions of Microsoft Office and is COLF and TAP Accredited and a member of The British Learning Institute.