Critical Path Analysis in P6 - 5 Things I Wish I Knew Earlier

hi it's Michael and welcome to another video tutorial here at planner tots online training today we're talking about critical path analysis in Primavera p6 and I wanted to share with you five things that I wish I had known earlier in my career with Primavera p6 if you're ready let's go through them the first thing I wish I knew was that decimals matter let's go into p6 and I'll show you exactly what I'm talking about so here's a very large energy construction project in Primavera p6 and I wanted to show you that at first glance if I scroll down and have a look at my float values and my original durations everything looks pretty normal here but we might have some things hidden if we turn on the decimals so let's go into edit user preferences and time units and we'll add two decimal places here to our durations great now when I do that have a look at my total float values this should be an indicator for you right now total float values where they used to say 1 now they say point 0 8 5 days hmm that's curious what's going on there might be something to do with the calendar and if I scroll back up to this project and go to a particular area there we go the foundation works and I have a look here at my numbers most of my durations are full integers however down here and in the foundation works I have some 1.25 days or two point five or three point seven five days now what's going on there well showing the decimal can lead you to uncovering some important things about how your projects been built so for example if I open this up a little bit I can see my calendars now and I'll notice that my calendar throughout is pretty much this 10 day six hour but for this section you know and this for demonstration purposes I've switched it over to the eight hour buy five day calendar and by switching that calendar I actually change these duration values and let me show you what happens when I switch this calendar back just do a fill down have a look now my values are back two whole numbers so displaying those decimals can lead you to find inconsistencies with your calendars as well and I think that's going what's going on with these total float values some of these calendars start at different times of the days and we're using a few different calendars in the project so in uncovering things in your project schedule decimals matter the second item I wish I'd known earlier in my career as a p6 planner is that the truest critical path is the longest path what do I mean let's go and look anybody who's used Primavera for a little bit knows that you can go into filters and turn on the critical path filter so when I do that here's my projects critical path now this is a large project and this seems like a very short critical path for the size of this project and I have a look at my activity count I only have 5 activities now if I go in here and uncheck critical and turn on rather the longest path I got a very different result I got a hundred and nine activities now why is that why is my critical path different based on based on total float or based on the longest path what's happening here in this project is that this project actually has a must finish by date set and you can see that we must finish by the 30th and we're actually finishing a day early so most activities on the critical path will actually have positive float because of this must finish by date we're finishing one day early so in fact we have one day of positive float on most of the activities and that's why in this case we're much better off to use the longest path here so that we actually show the true critical path and it's not based on total float but it's based on the longest path through the project schedule the third thing I wish I'd known earlier in my career was that multiple critical paths mean more risk to the project what do I mean by that let's have a look at p6 so I'm back in Primavera p6 and I want to look at my critical path in such a way as I want to see if I have overlapping critical path activities how do we do that well I still my longest path filter on and what I can do is simply go up here to the customize area and open that and simply just hit delete to remove any grouping and then I'll simply sort this whole thing by start date and what this gives me is a very clear and very structured critical path picture now what I want to look for is areas where I have overlapping activities now here's a particular area here I have lots of overlapping activities I'll zoom in a little bit so you can see that this isn't necessarily a dissection with multiple critical paths but for any place where have activities that are overlapping starting those activities on time each one of them in ending them on time each one of them adds an element a higher element of risk to my project they all need to start on time and they all need to finish on time I've really you know multiplied my risk by six here because I have all of these activities overlapping at the same time and if we scroll up we can probably find another example of that again up here two activities that are going on at the same time that are on the critical path so having a look at your critical path in this sort of view can help you quickly find the riskiest areas to manage those multiple critical paths and overlapping critical path activities number four the clock is your friend let's have a look the clock can be a really handy tool for helping you analyze issues with your critical path issues with dates and issues with calendars so here we have a situation where we have either 0.85 days of total float or 1.4 7 days of total float and I'm not really sure what that is and why that's going on and why I have five point nine nine nine days let's go up to user preferences and on the dates tab here we want to turn on this 12 hour clock so here we have our clock now and every date now has a timestamp next to it for start or finish dates now this can be really handy to help me understand what's going on here we have activities finishing at 5:00 p.m. starting at 8:00 a.m. but here we have activities that are finishing at 7:00 a.m. and what's going on with this 1.47 days of total flow back here in the projects view where I'm looking at my project and I'm looking at the dates tab if I look at my must finish by date now the project must be finished before 7:00 p.m. on June the 30th and it in fact is finished at 7:00 a.m. on June the 29th so that accounts for one point for seven days a total float it's the difference between June 30th 7 p.m. and June 29th 7 a.m. Primavera has turned that number into a fraction so if you need to analyze things at a detailed level it's a great idea to turn on those decimals as well as to turn on your time stamp the last thing about critical path analysis that I wish I knew was relationship columns let's go have a look in p6 we're looking at some of the construction milestones up at the top of the project and we're looking at this completion of Roth Foundation concreting milestone it has a predecessor and a successor but what I can't tell from this view is anything about whether the date of this finish milestone is actually affecting the date of the successor the basement wallet column right click on any column customize the columns let's get rid of ID WBS we don't need those activity status are not interested right now driving we want to add that guy in as well as we want to add start and finish dates click OK on that on the right hand side we want to do the same thing click apply here we have the completion milestone for the raft concreting the incoming predecessor is a driving predecessor that means that this finished date on this activity August 11th is forcing this activity to get its own August 11th finished date however the successor here is not a driving relationship the successor doesn't start immediately after in fact it has a one day leg this is August the 12th whereas this is August the 11th putting these columns up here allows you to do some really quick analysis let's do one more completion of auxilary building now we're looking at more relationships so we have a number of incoming predecessors this driving checkbox indicates that the finished date here of this activity is driving the milestones finished date this milestone is also driving two other activities to start but it's also got a predecessor or a successor here but it's not a driving relationship so having that driving relationship and the start and finish date columns there is incredibly helpful to help you understand what's going on and that sums up this tutorial thanks for watching I hope you learned a lot and make sure to check out the blog

Channel: Plan Academy Inc.

Views: 136,827

Rating: 4.9161425 out of 5

Keywords: Primavera P6, Critical Path Method, Project Management, Critical Path Analysis, Primavera P6 Professional, Primavera Systems (Business Operation)

Id: 9HJV9037tX4

Length: 9min 54sec (594 seconds)

Published: Fri Jan 08 2016