Learners will discover the key project scheduling techniques and procedures including; how to create a network diagram, how to define the importance of the critical path in a project network, and defining project activities float. Also covered are the fundamentals of Bar Charts, Precedence Diagrams, Activity on Arrow, PERT, Range Estimating, and linear project operations and the line of balance.
Schedule Application: Custom Tools
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Do curso por Columbia University
Construction Scheduling
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Technology Applications for Scheduling
Dareen Salama, of the STV Group, discusses the technology applications used for scheduling. Dareen provides an overview of the applications used for scheduling development, schedule analysis, sharing and collaboration and visualization.
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Ibrahim Odeh, Ph.D., MBAInstructor, Department of Civil Engineering and Engineering Mechanics, Columbia University
Director of Research and Founder, Global Leaders in Construction Management
Now there's commercially off the shelf tools that are available, but
there's also that approach that you can develop your own, depending on your needs.
So let me talk about the need here.
Typically in different projects from what I've seen
there is mostly a contractor requirement to have a cost loaded schedule.
But the challenge there is that the growth of the project and
the complexity of the project, it's not as easy to cost load a schedule,
for example, for a large project that's 22, 000 line items.
That's virtually impossible to update every month, it's very, very difficult.
So you end up with either lack of data from a cost loading standpoint,
or you're really not getting the deliverable that you need.
And you spend so much time checking that cost loaded scheduled
that you end up not really utilizing it to the greatest to the extent possible, or
if you're lucky even sometimes you don't get it.
So what did we really do to solve that challenge for us is that if we don't have
cost-loaded schedule, we need to analyze the data from the schedule somehow.
We need to figure out what is it that is causing the project to be delayed.
We need to establish some trends.
And we do have enough data in the schedule to allow us to do that,
even if it’s not cost related.
So what we did was looked at a methodology called earn duration.
We've looked at it and we've modified it for our own use and
we monitored how accurate does the response from that method and
from that tool give us in terms of predicting how much the project is delayed
and the forecasting the probability of the project meeting its schedule.
So I'm going to show you some samples of that.
So what that shows here in all this data,
the most important part is it's all extracted from the schedule.
So whether we developed the schedule and its updates or the contractor developed
the schedule and its updates, all this data is coming from that schedule.
We are not recreating any type of data.
And if you're familiar with the earned value,
then you're only looking at duration data.
We're not looking at cost data, this is all based on duration.
So what this is saying here is that this green curve is based on the baseline,
based on the early dates that are within the baseline.
The baseline said that I'm going to complete my project,
given this trend of using up duration, using up days by February 24th.
Today, which is my data date is September 1st.
And today, I have spent 333 days on the project.
And both of these are coming from, again,
directly calculated from the number of days spent on a project given for
each activity, based on the baseline and based on the actual.
So clearly the activities that I've completed now are taking longer because
it exceeded the green line, are taking more time than I thought they would.
But not only that, the work that I've completed within
this time period is actually this gray curve right here.
It's actually that earned duration, so I finished in 333 days
what I should have finished in 243 days.
That's really what this curve is telling you, not going to go into the detail and
complexity of calculation behind it, but this is just to give you an idea that
you can analyze the schedule in many different ways.
You have to figure out what is the best way analyze it for you.
Now the purpose here is am I using my time efficiently, and
if I continue with this trend, am I going to meet my date or not?
So clearly here if I continue with this trend, I'm not going to finish on time but
I'm actually going to be delayed.
Now this is another example, but if you notice here this
axis is showing the total duration rather than the cumulative days spent.
So here the total duration percent complete is I have spent
20%, but I am actually right here.
I am behind.
I've spent 119 days, but I have earned 101 days.
This work that I finished in 120 days, based on my baseline schedule,
I should have finished it in 100 days.
So I am losing these 20 or 18 days.
So here, this Days Lost is the 18 days.
The Project Progress Index is I'm about 28% complete, but
I've actually spent, so this is that 28% complete.
But I'm actually saying that I'm about 38%.
The contractor based on a lot of people when get the schedule,
they look at the end date.
They look at I got the schedule, where is the latest schedule update?
Quickly, let me see where is that finish dates.
So the finish date is telling you
I'm forecasting I'm going to finish on December 2nd.
So I know my baseline is December 1st, but I'm actually going to be one day late.
So that's what the contractor is telling me four months into the project.
Well, great.
A lot of people go by that date.
They look at that date in the schedule,
they say, well the CPM schedule is saying that.
But that's not necessarily true, is it?
The contractor will keep telling us I'm going to meet the date,
I'm going to meet the date.
But what's really happening is they're either eating up float or
they're assuming they're going to increase their progress.
But how many people really do improve their progress after a trend of
ten months working in certain way?
Do they really ramp up in those last two months?
I wouldn't necessarily count on it.
So what the contractor is saying is that I'm going to be delayed one day.
What the analysis is really saying is that you're actually going to be delayed by 18.
You're actually delayed by 18 already today.
But in the future,
if you continue with this trend you're even going to be delayed even more.
We're sticking to that 18 days assuming that we're conservative.
We're optimistic and the contractor will really
pick up their pace to match their baseline progress moving forward.
These are just other sample curves that give you the same idea, so
again green here is the plan based on the baseline.
Gray here is the earned duration, and
the earn duration is really telling me that yes, I have spent 424 days,
but I'm really earning 311 days.
So that work that I finished in 424 days should have been completed in 311.
So, I've wasted a lot of time there.
Now I spoke about that this method is not really commonly used in the industry.
It's really used by STV, so far from what I've seen.
So we were curious, how does it do on a historical trend standpoint?
Is it accurate?
How accurate is it?
And a lot of people asked that question.
So what this curve shows you here is that this is what
the delay in calendar days based on each update.
So each of these dates right here, this X axis, represents one update, one schedule.
So here I got one whole schedule that includes a baseline and
includes an update.
Based on that update, what is my evaluation?
So on March 1st, the update that we received said from the contractor.
So if I look at that finish date of the CPM schedule based on
the contractor's submission, says that they are delayed 110 days.
Then for some miraculous reason, on April 1st, they said, no,
no, that was a mistake.
I'm not delayed that much.
I'm only delayed 44 days.
So they clearly backed up there, and said, no,
I don't want to report this delay right now.
I'm going to tell you that I'm only delayed 44 days.
Great.
When we're analyzing the schedule, what we're really seeing is that
no you're actually delayed a little bit more than that.
You're delayed about 52 or 60.
And then we keep moving on.
The contractor keeps saying, no, no, I am doing well, it's still 44 days,
it's still 44 days, it's still 44 days and so on.
They keep telling us we're doing well.
You notice that the orange curve which is based on the actual dates and
the actual durations of which activity.
So again, pure duration data Is looking at and saying, no, no.
I'm seeing here, a hundred, you're actually a hundred days back,
delayed, you're actually a hundred days delayed.
They're saying no, we're actually 44 days delayed.
That means, they're eating up their float and
this is based on evaluating their performance and
not just what they're saying the date they are going to finish at.
So we kept evaluating this on a monthly basis.
Every month I'm looking at what the metric from earned duration has set and
what the contractor is reporting.
And at the end of the day you really see that there's no running away from it.
By the end of the project, they couldn't say I'm delayed 44 days anymore,
because 44 days are gone already.
I can't say that anymore.
I have to really start telling what's the real narrative,
what's really happening on the project.
If I'm not so optimistic about my performance,
if I'm not going to be performing at double my rate just to meet the schedule.
So, we find that this a very important tool in really showing your contractors,
or showing your teams, or your subs that the probability of you
continuing with this trend will not help you in meeting the project schedule.
So that really helps in getting ahead and from an analytical standpoint rather
than having a bunch of people talking about their opinions in meetings, but
really show the data.
Really show what is your opinion based on and that would really help open a lot of
people's eyes on no, this is what's really happening on the project,
and we need to start dealing with it with corrective action.
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