Create Your Construction Invoice Example for Planning Effortlessly

Construction invoice example for Planning

in today's video we're going to talk about the basics of how a construction schedule is put together I'm going to explain what a critical path schedule is by first explaining how a schedule originates as well as the meaning behind some of the scheduling terms involved today we'll be looking at a basic example of some construction activities and their corresponding relationships in future videos I'm going to expand on this information with an indepth series of how to establish a baseline schedule then how to manage and update complex construction schedules inside actual construction scheduling software so let's go all right so first we've got to understand how a project schedule originates which is dependent on the type of owner or client we're working with the type of contract we'll have and the type of project we're working on no construction project is typical so no project schedule is going to be typical you could be building franchised construction projects which is in essence the same building or project over and over over but variables such as where the project is located what the local labor workforce looks like what time of year you're building could all drastically impact what the Project's schedule looks like so let's assume we have an owner or a client who knows nothing about construction but wants to build a building this owner approaches both an architect and a general contractor or construction manager for this project and the owner is going to ask how much it's going to cost and how long it will take to design and build this is all critical information to the owner because the owner is typically building something to get a return on their investment the owner is looking at the cost of construction and potential profitability from that project the owner is also going to be looking for a schedule as part of their consideration to take this idea to actual construction So the faster this project is designed and built the faster the owner receives their return on their initial investment so schedules are just as important to owners as project costs are because because the cost of a building sitting incomplete could financially impact this owner who is not earning profits on the building when they potentially could or should be so this is why commercial construction contracts are typically and most often written with defined project completion dates whether there are liquidated damages or other consequential damages Incorporated and tied to those completion dates is just another topic for another day so just as a general contractor can provide a square foot price estimate of a building in programming or conceptual phases of construction based on previously completed projects of a similar scope they can do the same thing with a schedule for instance let's say we know the owner wants to build out a commercial retail space and we as the GC or cm are given the approximate square footage of this potential project well we've recently completed three similar projects at a similar square footage we can compare the timelines of those previous projects as well as incorporating new variables that we may know and this is how we we would generate a rough schedule or overall duration of this project to help inform the owner's decision-making so as design continues we start to understand more and more specifics to the project thus we can refine the budget through conversations with key subcontractors as well as refining the schedule through these same conversations the closer a GC or CM gets to compiling final bid documents the more refined the schedule should become with clear expectations and Milestone dates and then at this point the schedule starts to shift from what was broad durations to now incorporating these Milestone dates as well as specific activities General Contractors and construction managers work out a presentable and manageable schedule which ultimately gets incorporated into the bidding documents that all contractors will be submitting their pricing against so when General Contractors construction managers trade contractors and subcontractors are bidding on commercial construction projects they're not only committing to certain budgets with with the owner they're also committing to certain schedules site logistic plans and other contract documents that they've all reviewed and said yes we all agree we can do this and meet these parameters so let's pause here for a moment and talk about why so many construction projects seem to have highly aggressive schedules meaning shorter time frames now at some point every individual or company Working On Any Given project agreed and bought into some baseline schedule prior to committing to that project however through the competitive bidding process it continues to not only pinch profits but also these schedule durations forcing these schedules to be shorter and shorter so the bigger question is how many companies are overcommit and therefore forcing underperformance in Failure through this bidding process we hear so many projects in the news getting into lawsuits because they've missed their turnover dates again a good discussion for another day Okay so we've learned that project schedules are influenced through buying from all parties and are UL ultimately then established by the general contractor construction manager in a set of bid documents to meet the needs of the client while still holding reasonable time frames that everyone can uphold so how do gc's and CMS take all this information from past projects from subcontractors from this current project scope combine all this knowledge and generate the most reasonable yet competitive schedule well they all utilize a scheduling practice known as the critical path method which I'm sure youve heard the term used before the critical path is the longest amount of time it'll take to complete a construction project through a series of activities with zero float or slack that must happen in a sequential order float and Slack are interchangeable terms and I'll explain them in just a minute the term longest in that previous statement confused me when I was first learning about CPM schedules but the keywords to pay attention to are really float and slack also I don't really think there's a good way to verbally explain M CPM schedules at least for me without a good visual representation to go along with it but I'm going to provide a little more context before we get into that example so this critical path is based on a series of construction activities that must happen in a sequential order to complete the project an activity in a schedule is an aspect of scope that has been given a set duration of time but a construction schedule isn't one path of activities from start to finish it's multiple Paths of activities that originate from one single starting point and end at the same finish Point through a series of relationships with one another as you know multiple activities can be happening on a project simultaneously activities or scope all have different relationships with one another based on the sequence of how this building is going to be built only one of those paths though is deemed the critical path while the other paths have activities that have float or slack we call the One path critical because zero hiccups can happen on on that path or else it will directly extend the Finish date of the construction project so to reiterate activities that are not on the critical path have float or slack meaning that there could be potentially some hiccups or delays to those activities and the end date of the project will likely be okay now a project schedule is a living breathing document that needs regular attention and regular updating to ensure that the project is still on track the critical path can however change throughout the duration of a Project based on these real-time schedule updates so this schedule is comprised of a start date a series of activities potentially some Milestone dates and a finish date if you recall an individual activity is any defined scope of work with a set duration meaning that you have a task and an Associated time with it so how do these activities get their durations defined how do we know what time to assign to Any Given activity well construction workers or any worker for that matter have productivity rates and there are resources online such as RS means that track these productivity rates on a national scale with modifiers based on the city or state that you might be working in most companies track their own production rates to ensure that they're building out accurate schedules and budgets on future projects so let's look at an example of a productivity rate for installing a door frame and how it relates back to our schedule let's say it takes one person one hour to a door frame well that's our production rate now let's say our estimate captured 500 door frames on this project so if we do the math it would take one person 500 hours to 500 door frames which is the equivalent of about 12 1 half weeks or a little bit over 3 months well let's just say that doesn't work out with our overall project schedule needs and let's say that we need it done in approximately 4 weeks to maintain the flow of this project well we can't really just adjust productivity in this equation so the only other thing is crew size if we utilize a threers crew in Le of one person we cut the time by three 12 weeks turns into four weeks now you won't be doing this on every activity in your schedule but this is how you would use production rates to generate schedule durations you'd use this if you wanted to calculate or back check whether durations in your schedule are accurate or not I'm just sprinkling this into this video because production tracking is directly tied to both scheduling and a future video I'll make in regards to forecasting and profitability of a job which is the large aspect of project management so I'd argue that compiling an accurate construction schedule and understanding project sequencing is one of the most difficult tasks for majority of people to grasp when first entering the construction industry so just like anything this is a learn skill that you'll need to work on and develop over time project scheduling is your road map that influences not only what your project should be doing today but what you should be f focused on and planning months in advance ultimately the schedule needs to be a balance of having enough information to make sense to be constructible without too much detail that bogs down and confuses people too much detail might leave less flexibility to adapt to unforeseen changes when you need to update your schedule or activity relationships in the future now every project schedule should have at least two Milestones Milestones are points in time with zero duration associated with the activity and are there to establish a goal or a Target the two Milestones every project is going to have will be your start Milestone and your finished Milestone other Milestones may include structure being complete envelope dry in in-all inspections above ceiling inspections final inspections and more they're included as a straightforward measurement to determine whether or not the project is on track or not aside from your start date and finish date Milestones every other remaining activity will have a relationship ships to other activities in the form of both predecessors and successors a predecessor is an activity that happens before a specific activity a successor is an activity that happens after a specific activity now this might sound simple but the importance of the statement is because many people create schedules where activities lack either a predecessor or a successor these are considered open Loops in a schedule that could lead to inaccurate overall durations based on logic driven in the schedule or you're scheduling software so I previously mentioned activity relationships which is essentially how activities are tied to one another and there are four of them when it comes to scheduling the first activity relationship type is a finish to start or FS relationship meaning that one or more activities the predecessor or predecessors must all be fully complete before the following activity the successor May begin this is the most common type of activity relationship and we'll use this in our example shortly next we have a start to start or SS relationship this means an activity cannot start unless another related activity has started as well then we have a finished to finish or FF relationship this is rarely used but it means that an activity is only deemed finished when its related activity is also finished finally the fourth and last relationship type is a start to finish or SF relationship this is also rarely used but it means that an activity cannot finish until a predecessor activity has started all right so we've made it to our CPM schedule example now this example is a manual calculation of what construction scheduling software will do for us but we need to First understand how this works on paper so that we can understand what's happening behind the scenes in our scheduling software once you understand how to manually calculate how a CPM schedule works you'll likely never need to manually write out a schedule again because your software is going to work 10 times faster okay so this example has a starting Milestone this example has a finished Milestone this example will have eight activities in between which I'll label activity a b c d e f g and activity H so I'm connecting these activities together with lines which is how we would sequence this project as part of putting together this overall schedule these lines represent the relationships these activities have with one another each line in this example indicates a finish to start relationship meaning that the successor cannot start until all predecessors have been completed so for example activity G is a successor to both activities B and D activities B and D are predecessors to activity G meaning both activities B and D need to be completed prior to activity G starting activity G is also simultaneously a predecessor to our finished Milestone remember all activities except our start and finish will have both predecessors and successors now you see I have six empty boxes within each activity which are going to be used to calculate our critical path through what we call a forward pass and a backwards pass through the schedule these boxes will represent each activity's total duration or time Associated these boxes will represent the activity's early start or e as a number which is the earliest these activities can logically start based on their predecessor's finishing again this will all make sense in just a minute once we start putting this all into action so stick with me we're almost there these boxes will represent the activity's early finish or e f as a number which is the earliest these activities can logically finish based on the early start ES plus the activity's duration these boxes will represent the activity's late start or LS which I'll further explain shortly these boxes will represent the activity's late finish or LF which is the latest these activities can finish without extending the end date of the overall construction project schedule finally these boxes represent float or otherwise known as slack which is the amount of time and activity can be delayed without impacting the overall duration of the project the critical path will appear when we've calculated the path that has zero float so now we're going to start and we're going to manually find our critical path by completing what we call the forward and backwards pass through our network of scheduled activities so I'm going to start by adding in all of our durations to each individual activity until we have a duration associated with every activity next we're going to take a look at our starting Milestone and we're going to give this Milestone a zero because Milestones do not have durations associated with them so we're at our starting Milestone and we see that activity a c and e are all directly related to our start meaning that they can commence after our starting Milestone has finished since our starting Milestone has zero duration Associated these activities can start right away meaning that their early start or es will also be zero so we've officially started our forward pass through this schedule so if activity a has an early start of zero and an activity duration of six what is the earliest this activity can finish otherwise known as the EF early Finish Well if we take our early start of zero and add our activity duration which is six we get a total of six so the earliest this activity can finish is six days later so we're going to fill that in to our early finish date next we have activity C which also has that zero in the early start but this activity has a 4day duration which means that the earliest it's going to be able to finish is at that day four once we add our zero plus our four and we do the same thing with activity e now jumping back up to the top activity a has finished and its successor which is activity B is now able to start through the Finish to start relationship so activity a finished at day six which means that activity B can technically also start on day six so we carry that through to activity B's early start activity D and F are both successors to activity C so we carry the four through these as well then we fall back and we do our calculation for activity B's early finish or EF it started on day six it has a 3-day duration which means the earliest it can finish is on Day N okay so we do the same math in the same calculation for activity D and activity F now what happens with activity G activity G is a successor to both activity B and activity D this means that g cannot start until both B and D are complete which means G is relying on whichever activity of its predic cessors is going to take the longest well activity B ends on Day N and activity D ends on day 8 which means that activity G cannot start until day nine since it's waiting on the longest activity to finish now the same goes for activity H its predecessors are activity e and activity F since activity e has a longer duration activity H is waiting on both to finish but the early activity H can start is when activity e the longer of the two is wrapped up so we transfer that day 10 to our activity H early start now again we drop back and do our calculations add Day N plus 2 days of activity we get day 11 adding day 10 plus 3 days of activity duration and we get day 13 so finally we're at our finished Milestone which is dependent on both activity G and activity H being completed well activity G can wrap up but the project won't be complete until activity H is also completed since H is ending later then our finished Milestone has to be associated with h which is on day 13 so we've determined the length of our project by completing this forward pass but we have not established what our critical path yet so we have to complete a backwards pass so essentially we're just going to do the same process we did for the forward pass but we're going to do it in reverse so the top was our early start and our early finish the bottom is going to be our late start and our late finish so 13 is where we ended up so we'll drop this in activity G and H's late finish in order to calculate our late start boxes we need to take our late finish and subtract the activity duration so for activity G we'll take that 13 and we'll subtract our activity duration which is 2 days and we'll get a late start of day 11 we'll do the same calculation for activity H we'll take the late finish of day 13 subtract our activity duration of 3 days and we'll get a late start of day 10 now we're just going to continue this process working backwards with these same calculations through our schedule okay I've gotten to a point where I've hit three successors to one predecessor but each of these successors have different late starts so what do we do here activity a has a late start of two activity C has a late start of three and activity e has a late start of zero well if you recall on our forward pass we took the larger of the two numbers when we were trying to figure out the early start of activity G it's the opposite Logic on the backwards pass will take the lowest number in any of these scenarios with multiple successors to one predecessor so in this case we're going to take zero and feed it back to our start milestone so we've completed both the forward pass and the backwards pass which now has given us enough information to calculate this float and slack that I keep talking about float or slack is calculated by taking your late start and subtracting your early start you can also take your late finish and subtract your early finish so for activity a we're going to take 2 days less zero days or eight days less six days and get two days our float for activity a is 2 days for activity B we take 8 Days less 6 days or 11 days less 9 days which results in activity B having 2 days of float as well so we calculate the float for all of our activities which now outlines a path of activities with zero float or slack along its entire sequence this is our critical path on this project so what this tells tells us is that if activity e takes longer than 10 days or activity H takes longer than 3 days it's going to directly impact and extend our schedule Beyond these 13 days so this tells me that we better keep a close eye on these activities if we want this project done in 13 days because these activities are not allowed any hiccups so on the flip side every other activity in this schedule that is not on the critical path has float or slack associated with it after we've done these calculations which means for activity a activity a can be delayed 2 days after it was originally planned to start without impacting the overall end date of day 13 it means that activity C can start 3 days after it was originally planned to start without impacting the overall end date of 13 days this should now better explain what a late start on the activity means activity G doesn't need to start until day 11 for instance however if we use up more float than activity or sequence can afford when we run the schedule update our critical path is likely going to change and our project end date is likely going to change the only way to recover on a critical path is to evaluate resequencing of relationships or to cut durations by using larger crew sizes if you're working on a project and the schedule is not up to date it's going to be difficult to determine if you're heading towards your contracted end date or not all right so this was your introduction into understanding the basics of construction project scheduling if you can grasp this then you'll be much better suited in understanding scheduling techniques inside scheduling software okay so that's enough for everyone's brain for today so I'll catch you in the next video and remember be better build better and bye for now a