GDTP Certification: Elevating Excellence for Engineers and Their Companies
GDTP Certification: Elevating Excellence for Engineers and Their Companies
Why is GD&T proficiency still lagging despite its importance to modern engineering? Blake Gorowsky of Pratt & Whitney weighs in on the skills gap and the value of certification.
Geometric Dimensioning and Tolerancing (GD&T) has proven itself to be a necessary and invaluable engineering skill. This reliable system of defining tolerances was developed during World War II, filling an important need across industries, especially as modern manufacturing requires higher precision for cars, aircraft, medical devices, and more. And yet, many engineers lack competency and certification in this essential skill for product design, manufacturing, inspection and iteration. Why the disconnect?
According to a recent survey featured in the ASME Open Journal of Engineering, even when GD&T is included in engineering curricula, just over 26 percent of instructors rated themselves as “extremely competent” in GD&T. And the topic is often put on the back burner by engineers who figure they can get by with just the basics of the discipline, or thinking that technology (e.g., CAD) will overcome the skill gap. Unfortunately, this is at a time when the knowledge of GD&T fundamentals is critically needed to bridge the gap between design intent and physical reality, ensuring that parts function and fit together the first time.
“It’s often thought of as a niche skill, without acknowledgement of its core necessity,” said Blake Gorowsky, senior technical fellow of model-based design and definition at Pratt & Whitney. “For that reason, it’s not well covered in engineering schools. The gap this core skill represents to the mechanical profession I liken to going through an engineering program and not learning calculus. It’s a crazy thought–calculus and GD&T are both critical to engineering–yet one is prioritized while the other is not.”
One of the core challenges in mechanical engineering is developing a functional product design and then translating that “design intent” into physical components that can be manufactured and inspected with absolute consistency. Before GD&T was fully defined and adopted in the 1950s, engineers primarily used coordinate dimensioning on their projects, such as X-Y coordinate and plus/minus tolerancing. This conventional method worked; however, it often created rectangular tolerance zones which were less functional and accurate, leading to assembly issues and increased scrap as non-functional parts frequently failed inspection.
GD&T shifted the design landscape at just the right time: Continued engineering progress in domains such as aerospace and electronics that required higher manufacturing precision eventually culminated in the publication of ASME’s Y14.5 standard in 1957, which became the world’s first standard governing geometrical tolerancing. From that point on, GD&T became the foundational language used by product designers to define geometry and functional requirements to manufacturing personnel.
Gorowsky took advantage of learning GD&T early in his career with John Deere, applying it daily in hands-on roles in CNC and sheet metal manufacturing before transitioning to quality engineering and metrology, and becoming part of the company’s global metrology leadership team. “I was interested in finding out why lasers didn’t cut as accurately as we needed,” he said. “That led me to looking at how to assess machine and part accuracy. From there I got into control systems, understanding thermal expansion, statistics and computational analysis of machine tools.”
Seeking to expand and codify his skills in design, Gorowsky sought his first GD&T certification (GDTP 1994 Senior Professional) before moving to Medtronic, where he shifted into design engineering and became a lead design engineer for cardiac and surgical products while also achieving the GDTP 2009 Senior Professional certification. During these transitions, Gorowsky found that knowledge of dimensional tolerancing was a foundational and transitional skill that allowed him to move seamlessly between the agricultural, medical, and aerospace industries. Beyond his primary engineering duties, Gorowsky enjoyed mentoring and instructing, and he has taught GDTP prep courses to colleagues to foster a “community of practice” and enhance organizational competency.
His technical expertise includes a master’s degree in mechanical engineering, focusing on materials science and computational analysis, as well as certifications in quality and reliability engineering, Agile, and Six Sigma–the data-driven quality management methodology designed to minimize process variation and eliminate defects. “I’ve studied dozens of subjects over the years, from GD&T to youth hockey coaching,” said Gorowsky. “I’m just one of those people who likes learning things.”
ASME saw the industry need for professional education in GD&T and introduced the GD&T professional certification (GDTP) program in 1997 to verify an engineer’s knowledge of ASME Y14.5. This certification established where GD&T skills separate general proficiency from validated professional capability. “There are a lot of engineers who say they have used GD&T and know its concepts, but certification takes that to another level,” said Gorowsky. “The GDTP certificate shows that you have a demonstrable competency, verified by an outside organization, that you’ve mastered the material rather than just learned the basics.”
Importantly, GDTP certification is also universally recognized by engineering professionals across diverse industries such as medical device, automotive, and aerospace, where dimensional management competency is directly related to a company’s bottom line. And it’s often a requirement. “At Pratt & Whitney, knowledge of GD&T is required for engineers,” said Gorowsky. “Having demonstrable competency in fundamental first principles is core to executing at your job and getting opportunities. The certification process helps build demonstrable competency and can be critical to personal career growth.”
The value-add of GD&T is near universal, with some situational context. In many basic applications, its impact on the final product may be minimal. For instance, an engineer designing a nacelle (a streamlined engine casing) on a toy airplane may prioritize assembly fit, ease of assembly, manufacturing cost and aesthetics, but not necessarily final aerodynamics. If two pieces that attach are slightly, but not noticeably, off, that’s generally acceptable.
However, the designer on a $400 million airliner has little to no room for error. A design engineer working on this nacelle project is using the common language of GD&T with colleagues, management, and suppliers to ensure success in a high-stakes environment.
The initial failure of the Hubble Space Telescope is a high-visibility example of the importance of GD&T. After the telescope was in orbit and the camera turned on, Hubble’s first pictures were blurry. It was found that the primary mirror was polished to the wrong shape due to incorrect calibration of a null corrector. A laser-measuring device designed to check the null corrector was ignored, and the faulty calibration was not detected prior to launch. The mission to fix Hubble took three years to organize.
“When a group of engineers are lacking in GD&T proficiency, there’s a lot of time spent resolving disagreements over how to interpret a drawing,” he said. “That’s time that could be better spent in other areas.” Without a shared, standardized language to define their product requirements, engineering teams may unintentionally develop problems instead of solutions.
Blake Gorowsky, senior technical fellow at Pratt & Whitney.
“Great engineering work is generally collaborative; you’re working with others to create the product your company needs,” said Gorowsky. “GD&T competency in an organization removes the friction that develops when not everyone is on the same page with product definition. You’re able to talk about solutions whether an individual works in design, manufacturing, quality control, or any supporting role.” GD&T certification just further builds competency in the language of design from each discipline’s perspective.
Gorowsky believes that when an enterprise encourages or requires its engineering staff to become certified in disciplines like Six Sigma and GD&T, it can see some positive results in its bottom line. “This may be my own observation, but I’ve seen how that commitment delivers quality and efficiency,” he said. “It leads to fewer drawing and design errors, smoother collaboration between departments, faster approval cycles, and reduced time to market.”
With industries moving toward model-based design and increased AI design augmentation, the importance of GD&T proficiency among engineers is likely to grow. Engineers are learning to use AI as an assistant, but humans will need to interpret results, identify AI hallucinations, and handle issues that require deep technical domain knowledge. “Technology is always a helpful tool, but it’s the engineer using it that will have to describe the product’s design intent, and that’s why it’s critical to have the confidence that can come from being a certified GD&T professional,” Gorowsky said.
For those just starting their careers, Gorowsky recommends they initially seek a Technologist certification, showing that they’re able to understand and interpret drawings to a particular standard. There are three certifications, 1994, 2009, and 2018. Each exam is tied to a specific edition and is not cumulative. A holder of certifications from 1994 and 2009 would also benefit from taking the newly released 2018 exam as well.
Earning a Technologist certificate is also a logical first step since it doesn’t have the work experience requirement that the senior-level certificate carries, which is three years of documented experience using GD&T. "This is the perfect time to learn GD&T and truly master the craft,” he said. “Over the next few years, as you refine your skills, you’ll naturally transition toward the Senior-level certification. By then, you’ll have the critical thinking and expert-level discernment needed in engineering."
In addition, GDTP certification separates engineers who may be adept at using digital tools from those that use their deep technical discernment to guide their use of agentic AI and model-based design applications to guide them effectively.
Many engineers build personal networks of colleagues as their careers develop. However, when they take their talents to other industries, they may be entering a field where their skills are unknown. “When you show your potential employer that you’re GDTP certified, that puts you ahead of the game,” said Gorowsky. “This is particularly valuable when the company is committed to meeting international regulatory requirements, such as ISO 9001, ISO 13485, or AS9100. In those cases, GDTP certification serves as documented evidence for auditors that the engineering team has the verified skill set required to maintain quality standards.”
Ultimately, GD&T provides a shared technical language that facilitates global collaboration, ensuring that designs remain consistent and functional even when shared across international borders and different manufacturing standards. “Whether working with teams in China, Mexico, India, or anywhere else, design intent is understood on all sides, even when different regional standards such as ISO or JADA are in play,” said Gorowsky. “In today’s world where teams working on a project are often spread around the globe, that’s critically important.”
John Morell is a science and engineering writer based in Los Angeles.
According to a recent survey featured in the ASME Open Journal of Engineering, even when GD&T is included in engineering curricula, just over 26 percent of instructors rated themselves as “extremely competent” in GD&T. And the topic is often put on the back burner by engineers who figure they can get by with just the basics of the discipline, or thinking that technology (e.g., CAD) will overcome the skill gap. Unfortunately, this is at a time when the knowledge of GD&T fundamentals is critically needed to bridge the gap between design intent and physical reality, ensuring that parts function and fit together the first time.
“It’s often thought of as a niche skill, without acknowledgement of its core necessity,” said Blake Gorowsky, senior technical fellow of model-based design and definition at Pratt & Whitney. “For that reason, it’s not well covered in engineering schools. The gap this core skill represents to the mechanical profession I liken to going through an engineering program and not learning calculus. It’s a crazy thought–calculus and GD&T are both critical to engineering–yet one is prioritized while the other is not.”
The Importance of GD&T Competency
One of the core challenges in mechanical engineering is developing a functional product design and then translating that “design intent” into physical components that can be manufactured and inspected with absolute consistency. Before GD&T was fully defined and adopted in the 1950s, engineers primarily used coordinate dimensioning on their projects, such as X-Y coordinate and plus/minus tolerancing. This conventional method worked; however, it often created rectangular tolerance zones which were less functional and accurate, leading to assembly issues and increased scrap as non-functional parts frequently failed inspection. GD&T shifted the design landscape at just the right time: Continued engineering progress in domains such as aerospace and electronics that required higher manufacturing precision eventually culminated in the publication of ASME’s Y14.5 standard in 1957, which became the world’s first standard governing geometrical tolerancing. From that point on, GD&T became the foundational language used by product designers to define geometry and functional requirements to manufacturing personnel.
Gorowsky took advantage of learning GD&T early in his career with John Deere, applying it daily in hands-on roles in CNC and sheet metal manufacturing before transitioning to quality engineering and metrology, and becoming part of the company’s global metrology leadership team. “I was interested in finding out why lasers didn’t cut as accurately as we needed,” he said. “That led me to looking at how to assess machine and part accuracy. From there I got into control systems, understanding thermal expansion, statistics and computational analysis of machine tools.”
Seeking to expand and codify his skills in design, Gorowsky sought his first GD&T certification (GDTP 1994 Senior Professional) before moving to Medtronic, where he shifted into design engineering and became a lead design engineer for cardiac and surgical products while also achieving the GDTP 2009 Senior Professional certification. During these transitions, Gorowsky found that knowledge of dimensional tolerancing was a foundational and transitional skill that allowed him to move seamlessly between the agricultural, medical, and aerospace industries. Beyond his primary engineering duties, Gorowsky enjoyed mentoring and instructing, and he has taught GDTP prep courses to colleagues to foster a “community of practice” and enhance organizational competency.
Is It Time to Earn Your GDTP?
High-level design engineering requires precise communication. GDTP certification validates your ability to define design requirements and tolerances with clarity, helping you stand out.
His technical expertise includes a master’s degree in mechanical engineering, focusing on materials science and computational analysis, as well as certifications in quality and reliability engineering, Agile, and Six Sigma–the data-driven quality management methodology designed to minimize process variation and eliminate defects. “I’ve studied dozens of subjects over the years, from GD&T to youth hockey coaching,” said Gorowsky. “I’m just one of those people who likes learning things.”
ASME saw the industry need for professional education in GD&T and introduced the GD&T professional certification (GDTP) program in 1997 to verify an engineer’s knowledge of ASME Y14.5. This certification established where GD&T skills separate general proficiency from validated professional capability. “There are a lot of engineers who say they have used GD&T and know its concepts, but certification takes that to another level,” said Gorowsky. “The GDTP certificate shows that you have a demonstrable competency, verified by an outside organization, that you’ve mastered the material rather than just learned the basics.”
Importantly, GDTP certification is also universally recognized by engineering professionals across diverse industries such as medical device, automotive, and aerospace, where dimensional management competency is directly related to a company’s bottom line. And it’s often a requirement. “At Pratt & Whitney, knowledge of GD&T is required for engineers,” said Gorowsky. “Having demonstrable competency in fundamental first principles is core to executing at your job and getting opportunities. The certification process helps build demonstrable competency and can be critical to personal career growth.”
The Tangible Value of GD&T Proficiency
The value-add of GD&T is near universal, with some situational context. In many basic applications, its impact on the final product may be minimal. For instance, an engineer designing a nacelle (a streamlined engine casing) on a toy airplane may prioritize assembly fit, ease of assembly, manufacturing cost and aesthetics, but not necessarily final aerodynamics. If two pieces that attach are slightly, but not noticeably, off, that’s generally acceptable. However, the designer on a $400 million airliner has little to no room for error. A design engineer working on this nacelle project is using the common language of GD&T with colleagues, management, and suppliers to ensure success in a high-stakes environment.
The initial failure of the Hubble Space Telescope is a high-visibility example of the importance of GD&T. After the telescope was in orbit and the camera turned on, Hubble’s first pictures were blurry. It was found that the primary mirror was polished to the wrong shape due to incorrect calibration of a null corrector. A laser-measuring device designed to check the null corrector was ignored, and the faulty calibration was not detected prior to launch. The mission to fix Hubble took three years to organize.
“When a group of engineers are lacking in GD&T proficiency, there’s a lot of time spent resolving disagreements over how to interpret a drawing,” he said. “That’s time that could be better spent in other areas.” Without a shared, standardized language to define their product requirements, engineering teams may unintentionally develop problems instead of solutions.
Blake Gorowsky, senior technical fellow at Pratt & Whitney.
Gorowsky believes that when an enterprise encourages or requires its engineering staff to become certified in disciplines like Six Sigma and GD&T, it can see some positive results in its bottom line. “This may be my own observation, but I’ve seen how that commitment delivers quality and efficiency,” he said. “It leads to fewer drawing and design errors, smoother collaboration between departments, faster approval cycles, and reduced time to market.”
With industries moving toward model-based design and increased AI design augmentation, the importance of GD&T proficiency among engineers is likely to grow. Engineers are learning to use AI as an assistant, but humans will need to interpret results, identify AI hallucinations, and handle issues that require deep technical domain knowledge. “Technology is always a helpful tool, but it’s the engineer using it that will have to describe the product’s design intent, and that’s why it’s critical to have the confidence that can come from being a certified GD&T professional,” Gorowsky said.
GDTP: The Credibility Advantage
A key element of GDTP certification is that it creates a clear partition between people who have worked with GD&T standards and know the basics, and those with verified proficiency to add value to the overall engineering process. “GD&T is familiar to just about any mechanical engineer since they’re likely to run across it in their design work,” said Gorowsky. “But experience with it doesn’t mean you understand it correctly. Certification demonstrates proficiency in that skill.”
Working knowledge of GD&T is important, but it doesn’t replace certification. “Often, you’ll look at a project and see basic errors in logic or notation that can lead to ‘friction’ as it enters the manufacturing phase,” said Gorowsky. “Those are reduced when it’s designed by a certified GDTP professional.”
He points out that it’s not uncommon to meet talented engineers who aren’t certified, but “I’ve never met someone who has passed the exam and who’s also bad at using GD&T.”
As most mechanical engineers look toward advancing their careers, the ability to show that you’ve mastered a skill crucial to the job is essential. ASME’s GDTP certification is divided into two levels: Technologist and Senior. The Technologist level validates an individual’s proficiency in interpreting and understanding drawings using GD&T language. The Senior level builds on this foundation, providing an objective measure of one's ability to accurately select and incorporate geometric controls into a design.
Both certification levels use closed-book, 150-question multiple-choice exams, with up to four hours allowed for the Technologist exam and six hours for the Senior exam. Certifications are generally valid for three years, after which recertification is required.
“Holding a Senior-level certification signals that this person can be trusted to apply design intent and handle the complex ‘edge cases’ that can develop,” said Gorowsky. “It’s not unlike earning a Professional Engineer license. You’re asked to be ‘in the room’ where major decisions are made about a project.”
Which GDTP Certification Is Right for You?
ASME offers two GDTP certification levels: Technologist, focused on interpreting GD&T, and Senior, focused on applying it at an advanced level.
For those just starting their careers, Gorowsky recommends they initially seek a Technologist certification, showing that they’re able to understand and interpret drawings to a particular standard. There are three certifications, 1994, 2009, and 2018. Each exam is tied to a specific edition and is not cumulative. A holder of certifications from 1994 and 2009 would also benefit from taking the newly released 2018 exam as well.
Earning a Technologist certificate is also a logical first step since it doesn’t have the work experience requirement that the senior-level certificate carries, which is three years of documented experience using GD&T. "This is the perfect time to learn GD&T and truly master the craft,” he said. “Over the next few years, as you refine your skills, you’ll naturally transition toward the Senior-level certification. By then, you’ll have the critical thinking and expert-level discernment needed in engineering."
In addition, GDTP certification separates engineers who may be adept at using digital tools from those that use their deep technical discernment to guide their use of agentic AI and model-based design applications to guide them effectively.
Many engineers build personal networks of colleagues as their careers develop. However, when they take their talents to other industries, they may be entering a field where their skills are unknown. “When you show your potential employer that you’re GDTP certified, that puts you ahead of the game,” said Gorowsky. “This is particularly valuable when the company is committed to meeting international regulatory requirements, such as ISO 9001, ISO 13485, or AS9100. In those cases, GDTP certification serves as documented evidence for auditors that the engineering team has the verified skill set required to maintain quality standards.”
Ultimately, GD&T provides a shared technical language that facilitates global collaboration, ensuring that designs remain consistent and functional even when shared across international borders and different manufacturing standards. “Whether working with teams in China, Mexico, India, or anywhere else, design intent is understood on all sides, even when different regional standards such as ISO or JADA are in play,” said Gorowsky. “In today’s world where teams working on a project are often spread around the globe, that’s critically important.”
John Morell is a science and engineering writer based in Los Angeles.
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