If you are the project manager for a commercial general contractor, one of your key responsibilities is to ensure that job gets done - put another way, it is your responsibility to ensure that the final quantity of all work is completed.

It stands to reason then, that project managers should be paying attention to quantities on our projects as they progress... Even without formal systems in place most project managers are tracking quantities whether they realize it or not.  If I asked you - how far along are the roofers?  And you say "they're about half done", you can say this because you have a general idea of the number of installed units the roofer has completed.

On simple or small projects, a high level or gut feel for where things are at is good enough have your finger on the pulse and to keep things moving... but as projects scale up in size or complexity, the risk associated with your gut being wrong grows and formal systems for tracking quantities become increasingly important.

What are Quantities in the First Place?

It's probably worth level setting with some common language.  When I refer to quantities, I'm talking about a measurable unit of production that contributes directly to the final installed project.  Quantities are tied to the direct work activities on site (division 2+) for things that show up on the drawings.

The two key attributes of a quantity are:

1. They are measureble
   (Square feet, lineal meters, spools of wire, etc.)
2. They contribute to the final product
   (Walls, pipes, concrete formwork, etc. )

Indirect costs, like moving material around on site, sweeping floors, or dewatering after a storm aren't activities that have associated quantities.  While you could measure the number of square feet someone has swept and compare that to the floor plate of the building, that number is meaningless because he's going to have to do it again and indeterminate number of times until the project is over.

Quantities further break down into two buckets - estimated/budgeted quantities and installed quantities.  

• Estimated (or budgeted) quantities are the total amount of the thing that we are measuring as calculated from the contract documents. We obtain these values by doing a quantity take-off from the drawings or the model.
• Installed quantities are the amount of the thing that we are measuring that have been completed to date on site. When the job starts the installed quantity is zero, and as the job progresses, the value of an installed quantity increases until the work is complete.

At the end of a project, the installed quantities will roughly equal the estimated quantities.  I say roughly equal because what is measured with a ruler on a piece of paper, and what gets measured with a tape measure on the jobsite can produce slightly different results.

The Value of Tracking Quantities

In the introduction to this article, I mentioned that there is risk associated with not having a firm grasp on the installed quantities of your projects.  Any good PM knows that risk equals dollars: managed well, those dollars become profit... managed poorly, we know where that can go.  Tracking and using that the information we collect to manage our projects can unlock value for the project team.  

Understanding Crew Productivity

Many general contracting companies will undertake a portion of the work as a self-performed scope to be installed by their own forces.   Productivity is the measure of installed quantities per hour of work.  If your company self-performs work, crew productivity is a major profit driver: high productivity means you are likely to make money; low productivity could lead to losing money on an activity.

Tracking quantities allows us to match the measured units up with field timecards to gain insight into the rate of production of our crews at a given point in time.  Understanding how our crews are doing allows us to forecast where the budget is headed and provides the opportunity to course correct if things aren't trending in the right direction.

Historical Information

If you work in a market segment(s) where there are similarities in the activities between your projects, then collecting accurate historical information about those activities can be valuable in preparing future bids.

Measuring final quantities and comparing those to the total associated costs allows us to understand the going rate for that activity.  For self-performed work, we can use labour productivity values from past projects for future bids, and for subcontracted scopes, we can use unit price information for early stage estimates for our clients, or as gut checks on incoming bids from trade contractors at time of tender.

Measuring Progress

Knowing the amount quantity complete for a given activity relative to the total estimated number of units allows us to understand where that activity is at relative to the overall schedule for the activity or the project as a whole.  Without an accurate assessment of quantities, we can't know with certainty if we will make our project milestones, or when to schedule follow up activities.

Should I track quantities?

I know what you're thinking...

"Yes, theoretically there is value in tracking quantities.  I get it... but it also seems like a lot of work.  Should I actually bother doing this?"

That's a hard question to answer because you are absolutely correct that tracking quantities requires a lot of work, and that work has a cost.  Someone has to be out there with a tape measure and a clipboard (or a laser and an iPad - this is the 21st century after all), and that person is going to want to get paid.  Worse yet, if you don't have a designated person, then it's going to fall on your shoulders to complete the measurements.

The answer to the question "Should I track quantities?", ultimately comes down to a cost benefit analysis for any given scope.  

• For self-performed work, will tracking and regularly reporting on productivity result in material improvement to efficiency on site? If so, then yeah you should probably invest in tracking quantities.
• For work that we regularly self-perform, would having a really good understanding of labour productivity and material consumption help us to win work in the future?
• Is your spidey sense tingling about a trade's ability to finish on time?
• If a trade on the critical path misses their scheduled window, will that cause a catastrophic cascade?
• If trades on the critical path slip, does that open you up to contract risks for liquidated damages, reputational harm, or other penalties?

If you answered yes to any of the above questions, then you should probably consider investing in a program to track quantities on your project.  

Nobody knows the project better than you do...  Every job is unique and comes with it's own nuance, you certainly know the make up of your project better than some schmuck on the internet.  At the end of the day, the person best suited to tell you if you should track quantities is, well, you.

What quantities should I track?

If you've made it this far, it's because you've decided there is value in tracking quantities on your project(s) and that the value you'll extract exceeds the costs of tracking the quantities in the first place.   Great!  Now what?

Broadly speaking, it almost never makes sense to track ALL of the quantities on your projects.  There are too many, and most of them are inconsequential in the big scheme.  Furthermore, you don't have enough hours in your budget (or enough people on your team!) to measure and count every single widget that goes into a construction project.

Like most things, the Pareto Principle aka the 80/20 rule plays a big role in determining which quantities you should elect to track.  The first step is figuring out which are the 20% of activities on your project represent the 80% of the risk and opportunity.  When considering work performed by others, break it down into the individual activities of the trade, instead of looking at the trade scope as a whole - as an example, don't track "electrical work", instead consider pulling feeders, wall rough in, and hanging lights separately.

Make a list of the activities that have the biggest potential impact on your profitability or schedule performance - these are the activities to key in on.

Once you have established the activities that merit having their quantities tracked, the next step is to determine the unit of measure we plan to use and how exactly we will measure it.  

Here we run into our next trade-off - measuring accurately, or measuring quickly.  

Measuring accurately means choosing a unit of measure that can be compared against an hour of work for an individual or a crew.  When we are interested in understanding productivity, its imperative that we select a unit of measure that is very granular, such as lineal feet, square meters, or discreet elements like the number of light fixtures.  

Measuring quickly means choosing a broad unit of measure that is most useful in understanding work days remaining for a scope of work.  This unit of measure should still be discreet - having an initial estimated quantity to compare against, but where a rough estimate is good enough to gauge performance.  Examples of quick units of measure might be number of suites in a multifamily building for electrical rough-in, or number of gridlines for an excavator.  Measuring quickly is most useful for monitoring progress.

Your objectives for measuring in the first place, and the resources you have available to dedicate to performing the measurements will guide you in deciding if you should measure accurately or quickly.

In Conclusion

Quantity tracking on construction projects is a exercise that can unlock great insights about your projects including ways to maximize profit and stay on schedule.  Tracking quantities helps us understand crew productivity, provides historical information for reference, and helps us to understand overall job progress.

Selecting the right quantities to track, and the right methods to track them is important to ensuring that the value we are realizing is greater than the costs associated with collecting the information.  Every job is different and the right quantities to track requires thought.

In a future post, I'll take a look at some tactics to compile accurate quantities effectively, how to leverage quantities we are recording day-to-day, and how to ensure that the information that we want to track is actually being tracked.

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