Truss Designers: The Marines of QC


Truss Designers: The Marines of QC

Beyond spotting their own errors and minimizing headaches and guesswork for your production line, truss designers also have the ability to make or break your company through the quality of their designs.

Think of that 45-unit single-family development as the beaches of Normandy, or that 150-unit apartment complex and parking structure as the Kandahar Region of Afghanistan. Both projects are fraught with potential dangers and unique challenges, and both must be overcome successfully in order for your business to thrive. Who do you choose to undertake these monumental challenges? Easy, you choose your best and your brightest: your truss designers.

The first two articles in this series looked at what it means to have a formal quality control (QC) process and the benefits component manufacturers have witnessed since implementing one in their production facilities. This article will wrap up the discussion by exploring how your truss designers are your first, and best, line of defense when it comes to QC (your QC Marines). Further, it will look at the ways in which your truss designers can help or hinder your production QC process. Finally, it will explain how your designers actually put the capital “Q” in QC.

Designers Are Your First Line of Defense

It’s logical to focus your QC efforts first with your designers because they are at the beginning of the production process. “It’s cheaper to fix a designer’s mistake in design than it is anywhere else in the process,” says Dan Morris, Design Manager at Apex Technology. “To find and correct an error takes just a few minutes of review, but every step beyond that compounds the problem and cost to fix it.”

Dan Holland, President of Clearspan Components, is quick to point out that what designers do is greatly underappreciated. Not necessarily by the company owner, or by their coworkers or peers, but by the customers. “The concept of truss design appears simple to the outsider, and sometimes there doesn’t appear to be a great deal of variation,” says Holland. “However, there’s a large volume of it that needs to be done with a wide variety of subtle technical and software details to keep track of.”

By way of example, he points to a recent multi-family project he completed. The project had close to 200 unique designs; none of them were particularly complex to the casual observer, but the opportunity to make a mistake was high given the sheer number. “Unfortunately, any error by the designer is inexcusable,” points out Holland, “because their error can have such a significant downstream ripple effect from ease of installation to the cost of repair to fix a design problem.”

Morris concurs, “With a mistake during production, you can fix it. With a mistake during delivery, you can repair or replace a truss. However, a design mistake can threaten to have to redo the whole project.”

A good example Morris points to is a truss designer using the same label for two different truss profiles. If it isn’t caught immediately, the production line will most likely build two of the first profile, and ignore the second. There is no error for the QC process to catch, and no amount of visual inspection will alert someone to the fact a truss profile is missing. It likely will not get caught until the truss is installed. “The worst case scenario is you end up having to call a crane back out to the jobsite,” says Morris. “That represents a significant cost in time and materials for both you and your customer.”

So, the first challenge for any design department lead is to have a process in place that ensures every designer is meticulous in what they do, even when the repetition may threaten to bore them to death. “Implement strategies to keep their minds sharp. Work with your design team to form techniques that help them keep a fresh perspective,” adds Holland.

“Limiting and eliminating mistakes from the design process also has the added benefit of building trust between your production and design departments,” said Morris.

Designers Can Make the Entire QC Process Easier

There are several things your truss designers can do to make it easier on the production side of things. Having a good checklist or established process in place to take care of low hanging fruit is a good place to start. “Our design process starts by establishing all heel heights, dimensions, etc.,” said Morris.

“We have found checklists to be very useful. In fact, we probably don’t use them enough,” said Holland. “We have also looked into automating aspects of the design process as much as we can to eliminate opportunities for some of the more common errors that the computer is good at finding and correcting.”

Morris added, “Next, we look at each builder’s specifications, from special bottom chords to pulling out extra material.” Knowing the customer’s unique needs is one key to ensuring they’re happy, so he tries to keep all the jobs from a particular builder going through the same designer every time.

Next, the designer needs to be familiar with the demands of the market where the job is located, whether it’s something driven by the building code or just “the way things are done.” For instance, Morris points out that, in Florida, they do valley sets on every job. “But in Atlanta, they don’t want valleys because it makes the truss package price too expensive.”

While it may seem too simplistic, it’s also important to make sure your designers know what lumber and plates you have in stock. “Your designers should know the species, grades and lengths of the lumber you have in the yard,” said Morris. “Through that, they should know your standard splice lengths and panel points.”

“Specifying a plate that isn’t in your shop can be costly, due to the production delays,” added Holland. “While you can sometimes plate up, you don’t want to do that on a regular basis.”

Beyond knowing the customer’s unique needs and the limits of your raw materials in stock, the designer can play a key role in the production QC process by ensuring all the necessary details are communicated in the shop drawings sent to the assembly line. “The designer isn’t usually present during the production process,” pointed out Holland. “If a dimension isn’t included by the designer, it leaves a bunch of guesswork for the production crew. Sometimes those guesses don’t work out so well and lead to greater problems later on.”

In some cases, having an experienced production line can be a double-edged sword. David Mitchell, Operations Manager for Engineered Building Design, explained: “As soon as they know what they’re doing, they may be more apt to make assumptions to keep production running smoothly. You try to teach them to build only what is on the drawings. Of course, that means the drawings have to be both correct and complete.”

To that end, plate placement details are a critical responsibility for the truss designer, one which can be overlooked at times. Mike Cassidy at the Truss Plate Institute (TPI) has conducted numerous third-party inspections at truss plants across the country. What he has noticed is that, while QC inspections (and thus, formal QC programs) look at predetermined “critical joints” in the truss, they do not necessarily look at other joints that may have issues.

For example, Cassidy points to joints with offset plates. “If the assembler isn’t given enough information on the drawing to know the plate is supposed to be offset, they may end up installing the plate symmetrically out of habit.” This may lead to significant problems in the field later in the life of that truss, if repairs are needed to improve joint capacity. “Partly, this can be addressed by the production crew knowing what to look for, and partly the designer needs to make sure the information is communicated correctly through the shop drawings that are created.”

If certain problems, like the offset plate details or specification of materials not in stock, become common, Morris recommends having regular meetings between your production and design managers. “They are in the best position to evaluate the effectiveness of the processes you have in place and to figure out a solution to eliminate the problem from occurring again.”

Designers Put the Capital “Q” in Your Quality

Beyond spotting their own errors and minimizing headaches and guesswork for your production line, truss designers also have the ability to make or break your company through the quality of their designs. “I can honestly say our company is only as successful as our designers,” said Mitchell. “The better the design and the easier it is to install, the more the framer wants to work with us.”

Mitchell is quick to point out that being preferred by the truss or product installers leads to a good reputation with existing builder customers and recommendations to other potential customers. “It’s the best marketing we could ever do.”

Putting a capital “Q” in the quality of your truss designs means different things to different component manufacturers, but to Mitchell, it simply means making the truss designs in the framing layout as easy as possible to install. “My first goal with any layout is to identify and eliminate potential framing problems.” He admits that the design software has come a long way, but it isn’t perfect. It’s up to the designer to understand how the software works and to know its limitations.

It’s also vital for the truss designer to identify the most effective and efficient bearing locations in every layout. “The most elegant solution is often the simplest one,” said Mitchell. “Whatever we can do to reduce bearing locations and reduce the effort the framer needs to expend during installation, the greater our success.” Another example Mitchell points to is load distribution. “If you can eliminate a girder to girder to girder connection, you not only make it easier to install, it’s probably a better built structure as well.”

Cranking out amazing truss layouts doesn’t just happen; it takes years of experience and a good amount of natural skill. However, just as in managing common errors, having effective processes in place can go a long way toward helping newer designers produce efficient layouts. “It all starts with a good analysis of the initial plans to identify the challenges that need to be overcome,” said Mitchell. “Not everyone has, or should have, the same process, but having a rational and easy-to-understand plan analysis methodology is the key.”

For example, Mitchell’s process is one of establishing all the variables, then picking a master truss in the middle of the roof and treating it as a template off of which he designs the rest of the truss designs as he moves in both directions away from that truss. “I make sure that first truss is designed as well as I can make it, from the number of webs and their locations to the optimization of materials and panel lengths. As I move away from it, I incorporate the variables I identified in the earlier layout analysis process until it makes sense to switch to a new truss type or truss layout.”

Mitchell admits that his way is not the way for everyone. It’s based on his years of experience, the needs and demands of his market and his customers, and his knowledge of the software he uses. Again, the important point is to have a well thought through analysis plan.

“I don’t think even most truss manufacturers understand how much time and labor a designer can save, both in the manufacturing process and the installation of the product,” said Mitchell. “Ultimately, a designer can have an immeasurable impact on your relationship with your customer, in both good and bad ways.” That’s what a capital “Q” in quality is truly all about.

Designer (“D”) Day

Clearly, your truss designers need to know how much you understand and appreciate the vital role they play in the quality of the products you manufacture, and the role they play in establishing and maintaining your company’s reputation for meeting your customer’s framing needs.

Consequently, it is very important to ensure you are giving your designers the planning, analysis and software tools they need to do the best job possible. As this article outlined, that includes everything from establishing best practice processes to help them catch and eliminate their mistakes; providing a feedback loop from the production side to identify and address missing or incomplete data on the shop drawings; and finally, assisting them in the development of a good truss design methodology they can use to ensure their design layouts meet your customers’ needs.