【한글자막】 PMP 수학 준비 - PMP 수학과 공식들

Out of all the project management classes that I've taught, the number one question that I get comes from this section where we're going to talk about the math in chapter six of the PMBOK, which is project schedule management. I get a ton of questions about Float and that's one of the things, the primary thing that we're going to cover in this section. Yes, you will have some questions on Float on your PMP exam, so you'll need to know how to do this little puzzle. I say puzzle because that's how I look at it. Rather than just saying it's math, think of it as a puzzle that you have to work out. Now, some good advice for you. First off, when you get one of these questions about finding Float, draw it out on your scratch sheet of paper and be very neat and precise on how you draw out the Float diagram, or the project network diagram, because you may have more than one question with the same network diagram. In addition, take your time and check your math. That's one of the great things about Float. You'll know if your answer is correct or not based on the end result. I'm going to show you how to do that. It's very easy. All right, so let's hop in here to this section, which correlates to chapter six in the PMBOK guide on project schedule management. See you in the next lecture.

Let's begin our conversation by talking about analogous estimating. Analogous estimating is like creating an analogy between two projects. It's not a very reliable estimate type, because it's kind of a guess. You're basing your current estimate on mast information, on historical information. So for example, we have these two different homes here, the landscaping let's say in these two different homes. And project A took 180 days to do all of the landscaping, a really big landscaping project. Well, project B is about 10% larger, so we're going to say it's going to take 198 days. We don't have a lot of information, this is a really quick, subjective way to do an analogous estimate. It's just real quick. With an analogous estimate, you're creating an analogy between the two.

Parametric estimating is where we use a parameter to predict the duration of an activity.

So for example, we have this light fixture that we want to install and based on our installation, based on our tests, we know it takes about two hours to install that unit, to go through the whole process of unpacking it and assembling it and actually installing it. And we have 10,000 of those units to install. So 10,000 units times two hours, that's 20,000 hours that we're predicting.

Bottom-up estimating means that we start at zero, and we predict the time for every activity in our activity list. Bottom-up estimating is the most reliable approach, but it takes the longest to do because we need a work breakdown structure, because from the WBS we get our activities list.

Now, let's talk about three-point estimates. In this lecture we will have some math. A three-point estimate is just an average. So, a three-point estimate requires us to have an optimistic estimate for an activity, a most likely estimate, and a pessimistic estimate. And then we average those estimates and that becomes our estimate, our three-point estimate for that activity. So, this takes a little bit of time to do.

The really important stuff that I know you couldn't wait for that you want to come in and talk about, float. Float is just a way of saying how long can I delay an activity without affecting the start date of the next activity or the end date of the project. There are three types of float.

First off, we have free float. That's an activity can be delayed without affecting the early start of a successor activity. Basically, how long can I delay this activity without affecting the next activity's start date. Then, we have total float. Total float means an activity can be delayed without delaying project completion. How long can I delay this activity and it won't mess up the in date for the project. Most of the time we're worried about free float. Project float's unusual, it's really easy. Project float means you can delay an activity without missing your deadline for the project. For example, you have a very low priority projects that's going the last 60 days and you have a year to get it done. You've got a big window that you can pick up and put down that project at your discretion as long as you don't miss your deadline of one year.

There are a few agile questions you'll need to know for the PMP, maybe one or two. They're not really tricky but I would be familiar with an iteration Burndown Chart, and without getting into all the back story of what's an iteration and what's a Burndown or what are we burning down, just know this is a Burndown Chart what you see here. What we're looking at, each bar represents how much work is left and what we call the iteration backlog. You can also do this for the whole project, so you might just see it called a Burndown Chart.

Great job finishing this section, a really big important section when it comes to math in project schedule management. We talked all about Float. We looked at analogous estimating, parametric estimating. We looked at three point and beta estimates, a little bit of math there, and then we talked about bottom-up estimating. Know those terms for your exam. Guarantee you you're going to see those concepts. Then we really dove in and we did Float. We looked at a simple approach to Float with our forward pass and a backward pass, and then you completed an assignment where you dug in and calculated flow. Finally, we wrapped up talking about burn down charts and velocity, so a lot of terms, a lot of information in this section. Know that business for your exam and you'll be in good shape. Great job. Keep moving forward.

Welcome back. How you doing? Hanging in there with this MASS stuff, knocking it out. I know we've talk about a lot of concepts so far, but now we're gonna move into even more concepts. So we're going into chapter seven in the PMBOK Guide Sixth Edition, which is all about cost management. So in this chapter, there are a lot of formulas, because we're really focusing on earned value management.

So let's hit these estimate types, which you've already seen for scheduling. But we're going to look at these in the context of cost. So we're not going to linger here, pretty easy stuff. An analogous estimate, recall it's an analogy between two projects. So we have this painting these houses for instance. We create an analogy. It's not real reliable. Project A was $560,000. Project B is about 10% larger, $616,000. So it's an analogy. It's similar type of work, like painting these two houses. And we have to have some historical information. Parametric estimating, we looked at earlier with time. Now we're looking at in the aspect of finances.

Okay, this is the lecture that a lot of people have questions on when I teach the PMP boot camp, and that's on earned value management.

A lot of formulas in EVM, earned value management. Also you might see this as earned value analysis.

Let's hop in here, and we'll look at our earned value management. We're going to walk through all these different formulas you should know for your exam.

All right. You are making great progress here as you prepare to pass your exam. I know there's a  lot of formulas, and again, I was not a math guy. So, I have to really slow down and take my time, and I had to memorize those formulas. I want you to do the same thing. If you're struggling with these formulas get some flashcards. Write out the formulas over and over and over.

Hi welcome to this section. Welcome to Chapter 10 of the PMBOK guide on project communications management. Now this one sneaks up on people. How can there be math in communications. I talk to Bob. Bob talks to Sally. What more is there? Well there's a really important formula that you need to know when it comes to your PMP exam and that's the communications formula.

That's really the only thing we're looking at in this section. But I wanted to just take this opportunity to talk about communications management for a moment. Communications management, really important for your exam. It's tightly related to stakeholder management because who are your community with? Your stakeholders.

Let's get to it and talk about the communications channel formula. This is really easy stuff, but easy, of course, doesn't mean that you shouldn't learn it and know it and be able to do it in multiple ways. Let me show what I mean by that. The communications formula is N times N minus one divided by two where N represents the number of stakeholders. Okay, so let's see this in action.

Welcome back to Project Risk Management. I have a very simple risk management question for you. Do you ever go play the lottery? Not really good odds, right, that you're gonna win the lottery. I did this for you; I went and bought this lottery ticket, and funny enough I hit three out of the six numbers. So that means I got half the numbers, I win 50%, right? Of course not. I think I get five dollars for this lottery ticket. So not a great investment, don't have much confidence that it's gonna happen.

Let's talk about qualitative analysis. Qualitative analysis, we're looking for just a quick subjective review. It's not very reliable. It's a real fast review of the probability and the impact of our identified risk events. So it's pretty

When we do qualitative analysis, what we're doing is we are qualifying the risk to go on to quantitative analysis. So qualitative is real shallow and quick, is this a serious risk or not? That allows it to be promoted onto quantitative.

Now let's talk about quantitative risk analysis. This is the more serious of the two. We're looking at larger, more serious risk events. We're looking at risk events that have gone through qualitative or when you've initially identified the risks, you can see it so serious, it should go on to quantitative immediately.

Quantitative means you are quantifying the risk. You're trying to see what's a true probability and a true impact. It often takes time and you might even have a budget to do some testing to see the true probability and impact. So quantitative, we're looking to quantify.

In this lecture, we're going to look at decision tree analysis. Decision tree analysis is a pretty simple approach where you're just mapping out possible outcomes of related choices. So we're going to look at a decision tree. We begin by the decision. We have a single node that's going to branch out into possible outcomes.

You reached the end of this section on Project Risk Management. There's a lot of math that we looked at in this section. We talked about our qualitative risk analysis with probability times impact using an ordinal scale, and then we know the outcome of qualitative. It promotes those risks to go on to quantitative. It qualifies. Quantitative is more serious.

Now let's talk about Chapter 12 in the PMBOK Guide, which is all about project procurement management. There's a little bit of math that you need to know for project procurement management. Probably the most important thing from this chapter on procurement management is dealing with contract types. That you really need to recognize the contract types. You're going to have a whole lot more question on contract types than you will about the math that we're going to look at in this section.

Let's talk about the point of total assumption. It sounds really scary and ominous, doesn't it? It's really not that bad.

Here's the idea. You are a builder. Okay, you're a builder and I hire you to remodel this big old warehouse. We're going to make into loft condos. It's going to be really cool. Well, I have a pretty good idea because I'm a real estate developer of what it's going to cost to remodel this building, but I want you to do the work because you have all of the laborers. You have the materials and equipment and so on and what you to do it. So you and I get together and we come up with a fee and you tell me Joe, I'm alright. I think I can get this done for $1.3 million. And I say, yeah, that's probably about right, $1.3 million. Now I know you have a little profit margin in there.

In this lecture, we're going to talk about build or buy decisions. Should you build something or should you buy it? Probably going to see this on your exam. It's not a hard formula, so let's take a look.

Great job reaching the end of this section on project procurement management when it comes to math. You know that projects are going to need to buy things, and when you buy things, you need to know how to do math. So, when you go into the consideration of buying things, whether in the real life or on your exam, you have to think about what's best for the project objectives, what's best for reaching the goals of your project.

In this section, we talked about just really two types of math. We looked at the point of total assumption, which basically is, at what point will the vendor begin paying for all costs overruns. And we looked at buy and build, and then you did an exercise, I hope, of solving should you buy something or should you build it.