Quality Control (QC)

From Wikipedia, QC is “a process by which entities review the quality of all factors involved in production.” ISO 9000 defines quality control as “a part of quality management focused on fulfilling quality requirements.” Merriam-Webster defines quality control as “an aggregate of activities (such as design analysis and inspection for defects) designed to ensure adequate quality especially in manufactured products.” The keywords here are review, fulfill, inspect, and of course, control. All are concerned with the quality being produced now.

QC, unlike commissioning, is generally considered the realm of the general contractor’s and their subcontractor’s internal quality programs, and most evident during the physical construction phase. Contractors rely on their own inspectors to ensure compliance with standards, codes, and project specifications, and to pass inspections performed by outside AHJ’s (authority having jurisdiction) for close-in, mechanical, and electrical inspections, just to name a few.

A quality control program is focused on delivering products and services now. It is focused on inspecting, measuring, and identifying defects and discrepancies that exist. QC looks at what the quality requirements are, compare to what is “measured,” or observe and flag defects or deficiencies. When these get repaired or otherwise resolved, the quality is fulfilled, and the issue closed. Of course, if the defect is a result of a project-specific cause, or if the issue is expected to be repeated without some intervention, then the QC inspector should make notifications to all concerned to initiate preemptive actions, but I would consider this more quality assurance related than QC. The focus of QC is on the present. It is to ensure quality requirements are fulfilled now for this specific project.

Quality Assurance (QA)

From Wikipedia, QA is defined in part “as a way of preventing mistakes and defects in manufactured products and avoiding problems when delivering products or services to customers.” ISO 9000 defines QA as the “part of quality management focused on providing confidence that quality requirements will be fulfilled.” Merriam-Webster defines quality assurance as “a program for the systematic monitoring and evaluation of the various aspects of a project, service, or facility to ensure that standards of quality are being met.” The key words here are preventing, avoiding, providing confidence, and, of course, assurance. All are concerned with the future and improving the production process over time.

QA programs differ from QC in that QA is a quality program that uses QC processes (reviews, inspections, tests, etc.) to verify (or fulfill) quality requirements. QC identifies the defect and QA figures out how to prevent recurrence. A viable QA program should encompass continuous process improvement sometimes described as DMAIC which stands for define, measure, analyze, improve, and control. It refers to a structured program that employs a means to define the requirements, measure adherence, analyze the cause of defects, improve to preclude recurrence, and control the new process. The focus is on the future. Ensuring quality requirements will be fulfilled. That products and services will be as good or better next time.

QA cannot exist without a quality control program since if you don’t measure and inspect what is performed, there can be no process improvement. QC without a quality assurance program can result in simply catching the same defects or deficiencies over and over.

QA/QC

The new interest in QA/QC has been to include independent quality inspectors into the site construction team to embellish and supplement (and not to replace) the contractor’s programs. Unlike typical level-2 commissioning where the commissioning agent performs routine, periodic site inspections to identify construction-related quality issues, a true QA/QC inspector is embedded within the construction staff and performs QC inspections in real-time as construction progresses.

Full time QA/QC inspectors have both the time and opportunity to witness all of the construction practices and not just finished products. They can drill down into all of the details of construction quality verification. Some examples are ensuring the correct stamp is on bolt-heads, that wire and cable are pulled correctly, that pipe hangers and spring-isolators are adjusted properly, and that ducts get sealed prior to being covered by insulation. Other examples include that nameplates don’t get covered or go missing, that all documents included with equipment deliveries are collected, stored, and compiled for future use, and that wire labels correctly match wiring diagrams. QA/QC inspectors use photos and other as-built documents to record infrastructure that has been covered within walls, under slabs, etc. They witness breaker injection tests using site-specific trip settings, verify pipes and fittings are installed and properly fastened and connected (alignment, deburring, cutting pipe threads, torqueing bolts, etc.), witness pipe cleaning and flushing, pressure testing, and TAB activities, and witness critical electrical connections are properly torqued, crimped or otherwise connected, and a myriad of other quality related services.

The definition of commissioning depends on context. These include commissioning officers for the military, commissioning ships for active service, commissioning art, paying a commission, and building commissioning. A search of various dictionaries found even more variations, most of which have nothing to do with quality. The intent of this article is to focus on building commissioning, and so I will reference ASHRAE Standard 202-2013 “Commissioning Process for Buildings and Systems,” which defines the commissioning process as “a quality-focused process for enhancing the delivery of a project. The process focuses upon verifying and documenting that all of the commissioned systems and assemblies are planned, designed, installed, tested, operated, and maintained to meet the Owner’s Project Requirements.” Interestingly, this definition does not mention quality assurance or quality control. It says commissioning is a quality focused process. It’s more than inspections and less than a program.

There are obvious reasons and benefits to combine both the QA/QC scope and the commissioning scope under a single contract. The scopes are interrelated with some potential for overlap, they require independent third-party inspectors, and they focus on the quality aspects for the most critical systems and equipment, namely mechanical, electrical, plumbing, and fire and life safety controls and the enclosures that hold them. Both are focused on quality and use similar tools from test equipment, to inspection techniques, and even field tablets, applications, and software. But not all commissioning providers make good QA/QC providers, and vice versa. A few select firms have the experience and qualified staff to perform both, but most do not. This is true even in the critical facilities industry where commissioning requires the most technically capable staff.

QA/QC tasks, and the associated technical skills and knowledge required to perform those tasks, are not the same as for a commissioning agent. QA/QC relies more upon construction-related best practices with less emphasis on facility operations and performance testing. You expect a commissioning agent to review the QA/QC reports for completeness (NETA, TAB, meggering, grounding, water quality, etc.) and to be an expert on operational performance testing. QA/QC would look towards the shipyard for talent where commissioning steers more towards the sailors.

QA/QC and commissioning should be viewed as separate and independent services — QA/QC is not commissioning, and commissioning is not QA/QC. This should be reflected in any potential provider’s organization as distinct and separate business units with separate management. A firm that offers both QA/QC and commissioning services should ensure that assigned staff have the requisite dual skill sets or are only utilized on commissioning or QA/QC assignments for which they are qualified.

There are some in the industry that feel there is a potential conflict of interest in allowing the QA/QC provider to also be the commissioning agent, similar to the debate between allowing the engineer-of-record to commission his own design. I have always maintained that a bigger potential conflict of interest exists between the general contractor and the commissioning agent who is verifying the quality of the general contractor’s deliverables, and I extend this argument to include QA/QC as well. It is fundamental for quality programs and processes to operate independent of production, whether production equates to manufacturing widgets or constructing critical facilities.

So, to summarize, quality control focuses, at least in the building construction industry, on the fine details of ensuring construction and installation practices comply with project specifications, codes, and construction best practices. Building commissioning begins during the design phase and ends at project completion, and encompasses more than construction and installation. Continuous process improvement is accomplished via “lessons learned” reports for use by the next project team. Quality assurance never ends. It is a program that continually improves the overall process, whether focused on reducing construction related issues, or in improving the design, construction and delivery of critical facilities, so that we perform better on the next project.

This article was originally posted on www.missioncriticalmagazine.com.