Construction on a mixed-use building (multi-family, office and retail) was underway, with thousands of embeds for the façade, equipment, riser attachments and stairs in process. Properly anchoring and connecting them to concrete, both for location and quantity, is of the highest priority for design and construction teams alike, and errors can be costly to correct after the concrete is poured. The ramifications of rework—which can extend to preventing a leaking curtainwall system or ensuring that mechanical/plumbing systems are coordinated with walls, cabinets and fixtures—is massive.
As field teams worked to install the embeds, a construction verification scan (a digital “compare and contrast” to the coordinated trade BIM model) revealed that on average, 8% of these critical concrete connectors were outside the project’s tolerances. They were then corrected as part of the regular pour sequence, before concrete was placed. These insights enabled the trades to stay on schedule not only for the pour but also for the installation of the façade and interiors in the following weeks and months.
While many of the most important decisions related to quality are made during the design and planning stages, not after the fieldwork begins, quality remains a priority during construction to ensure accuracy (i.e., no rework) that leads to schedule and cost reliability and certainty. One of the most important metrics to track quality is first-time quality, or FTQ.
The American Society for Quality (ASQ), which is dedicated to increasing the use and impact of quality, defines FTQ as the calculation of the percentage of good parts at the beginning of a production run. On an assembly line, it looks something like this: A four-hour shift and a cycle time of one minute would result in 240 units being produced per shift. With a first-time quality rate of 85%, the assembly line loses 36 minutes of available capacity, producing just 204 units. For this assembly line and other production processes, FTQ serves as the early signal that a process is out of control and enables teams to focus on those areas that need improvement. At that FTQ rate, the factory is uncompetitive: It is shut down, people are out of work, and the business closes its doors.
In construction, FTQ (or as it’s sometimes referred to, “zero punch”) is an approach to quality management that aims to eliminate errors entirely; in essence, it indicates the extent to which the elements on a project, or a portfolio of projects, are assembled and installed correctly the first time—no rework required.
As a forward-looking predictive measure, FTQ is a powerful metric in construction because it enables you to utilize leading indicators as opposed to lagging indicators of quality. Yesterday’s errors are a strong indicator of where to anticipate tomorrow’s issues. By knowing the performance of each trade and each element in their individual scopes of work, all in real-time, you can predict and therefore prevent those issues—and even new ones. Other tools, like end-of-month analysis and, even worse, overtime (OT) and change order time tickets, are by their very nature reactive. It’s like driving using your rear view mirror only—slow, crooked and not very safe. That’s why owners, contractors and subcontractors all have contingencies built in.
Data tells us that industry average FTQ for deck pours is about 94% for a high-rise concrete building, but that drops to less than 80% for wood frame projects. Eliminating those 6%—or 20% or more—of errors represents a significant opportunity for investors, owners and general contractors.
After all, building out a deck, then removing and then reinstalling it (plus all of the paperwork and staff resources required to recoordinate) is far more expensive than doing it right the first time. The general contractor, who may be relying on a sub of a sub to get the work done right, has to catch errors before they compound. The need to manually verify the hundreds of elements being installed on a jobsite each day (thousands per week and tens of thousands for the project) takes valuable time and focus away from higher-value activities.
Understanding FTQ enables you to understand performance of each trade (which may inform your choice of subcontractor moving forward) and enable improvements as you go. In addition, with FTQ data reported in real-time as work is being performed, trades can learn from their mistakes and can adjust their techniques or approach to prevent repeat errors as they go. With this approach, typically FTQ improves over the course of a project as each trade incorporates the feedback into their work. This saves a significant amount of money, time and frustration and the resources required to craft and oversee how an issue is resolved. In addition to increasing profit, you may also be able to do more work (projects) with the same overall staffing.
How to Drive FTQ to Avoid the Risk of Rework
SiteAware’s Digital Construction Verification (DCV) platform helps you measure and improve first-time quality. SiteAware calculates FTQ for concrete decks, for example, as follows:
* Elements refer to items installed in the building, as specified by design plans or shop drawings. In this example of a concrete deck, elements include embeds, PT tendons, sleeves, risers, formwork, etc.
* Elements verified in scan 1 are elements installed correctly the first time and do not include verification-in-progress or work-in-progress elements.
SiteAware’s DCV process looks at the element level across trades, which allows it to measure the project in a way that takes into account the full complexity and intensity of construction as well as the accompanying need for accuracy. By tagging and verifying each element, SiteAware DCV enables you to not only prevent errors at the point of origin but also gain a granular picture of construction performed—one that extends across the project (or portfolio of projects).
In doing so, SiteAware measures the percentage of elements installed correctly the first time. By looking at the element level across trades and tagging and verifying each element, SiteAware enables you to ensure not only that each element is installed according to plan— including dimensional tolerances, manufacturer’s instructions, and more—but also that the plans of different trades are coordinated—for example, verifying that an embed is installed correctly according to the plan and also aligns to other plans that intersect. By generating in-process actionable insights through complete visual and dimensional verification of decks, MEP systems, façade and interiors installation, SiteAware DCV removes the need for time-intensive spot checks that are prone to error. It answers questions like: Was a conduit box installed? When was it installed? Where exactly is it? Is it the right shape and facing the right direction? The result? You can not only measure but also improve FTQ.
Learn more about how you can use SiteAware to increase first-time quality and reduce rework.