Proving Performance: Why Integrated Systems Testing Matters

Before a facility can officially transition from construction to operation, every critical building system must prove it can perform as designed — not just individually, but together. That’s where integrated systems testing (IST) comes in, serving as the ultimate verification step in the commissioning process to confirm all systems interact seamlessly under real-world conditions.

An IST is a test supporting a demonstration of multiple systems interacting together as would be presented to an owner at turnover. There are various means of facilitating an IST. At the heart of these more involved tests is a simulation of worst-case scenarios, compelling building systems to respond and interact cooperatively as intended by design and resulting in a complete exercise of the sequence of operation (SOO).

The commissioning provider (CxP) is responsible for directing, observing, and documenting IST per the commissioning specification and the commissioning plan (Cx Plan). The CxP should approach IST in the same manner as he or she approaches functional and performance testing (FPT). Timing is critical, and IST should be scheduled so that the necessary commissioning team (Cx Team) members and other parties who are required or invited to participate in the IST can attend this performance demonstration.

Timing, scope and real-world scenarios

Though exceptions exist, such as partial IST demonstrations, integrated system testing commonly occurs following a successful construction phase and during the occupancy and operations phase. A partial IST may occur during the initial phase of construction for a partially installed system, which is later intended to be further integrated or simply completed.

A benefit of partial IST could be an early detection of issues and their resolution while minimizing potential impact on the construction schedule. The obligation of the CxP is to the agreed upon scope of work (SOW), and therein lies the expected depth and rigor for the commissioning process as expected by the client.

A critical element to a successful IST is demonstrating a completed system as would be presented to the owner. Any test is only as effective as the preceding installation. Testing an incomplete system would yield incomplete or ineffective results. Subsequently, any changes to installation following a successful test may nullify that test and its results. From this premise, IST is typically the last and most significant commissioning effort.

For IST to be truly comprehensive, the CxP must include in the test scenario operational aspects of every building system that would interact in a real-world scenario. Consider an example of “pull-the-plug” or “black site” emergency systems testing. This IST simulates a prolonged interruption in the delivery of electric utility power services to a facility and examines the responses of affected systems.

In this test scenario, the CxP might expect responses specific to the building type to include, electrical, plumbing, conveyance, and heating, ventilation, and air-conditioning (HVAC) systems, at a minimum. Specific actions triggered by the simulated loss of power may include automatic activation of the emergency power system, reduced elevator loads and cab use, a switch from utility to onsite water and sewage service, the shutdown of some HVAC equipment, and the transition of other HVAC equipment to an emergency mode of operation. All of these actions should be completed under previously established protocols and programming. To complete the IST, the CxP and Cx Team must evaluate and confirm correct responses from each building system within the parameters of the agreed-upon SOW.

Defining scope

An IST may not be considered as limited to only two systems, but instead inclusive for multiple systems. The CxP may benefit the commissioning process when considering the IST from the perspective of a single system looking out. “Looking out” from a system in this manner would provide the vantage for observing monitored points from various integrated systems to the depth of which would be determined by an SOW. For example, the CxP may be scoped to commission the fire alarm system (FAS) only. During a FAS IST the CxP may stand at the fire alarm control panel and observe alarm conditions initiated.

In such a scenario of scope limited to FAS, that is not to say the CxP is responsible for commissioning every other system that interacts with the fire alarm system. The CxP may verify the single point of contact between the FAS and a kitchen ansul system, such as the appropriate trouble or supervisory signal from the ansul system to the fire alarm control panel. Again, in this example of an SOW limited to FAS only, the CxP has successfully achieved client goals and executed the SOW without separately commissioning the kitchen’s ansul system. An IST may therefore involve a system that is within the SOW and fully commissioned and integrated with other systems that are not in the SOW nor commissioned.

An IST would not infer additional commissioning services based on integration with other systems. The SOW defines equipment and systems involved in the commissioning process, not design intent. This delineation of scope may appear subtle but is increasingly meaningful as building technologies continue to advance in an age of connectivity. Any meaningful conversations regarding project scope and client goals are best addressed early and documented within the SOW.

Continuing this logic, an IST may include multiple systems that are within the SOW and have been completely commissioned. The “looking out” approach may also be applied in this condition and the commissioning process remains similar. The most significant distinction between an IST of systems in SOW and an IST with partial systems in SOW is the necessary coordination and contractor participation during the IST event itself. Using the example of FAS-only SOW, if an issue were to arise with the kitchen ansul system, the CxP obligation is to document that issue from the perspective of the FAS and in this case would be a signal from a monitored point or a single set of contacts.

Verification of system integration may involve multiple buildings. In a campus setting, new building construction is often phased. The interaction of systems within a building is as significant as those new buildings interacting with one another as a whole. An example would be completing a central energy or utility plant ahead of a patient tower.

Demonstrating the emergency power system upon completion of the plant as a partial test has some value, but would not be considered a complete demonstration of the emergency power system until patient tower automatic transfer switch devices (EPSS) were complete and integrated. Again, here the CxP can rely on the SOO when determining how to facilitate a complete system demonstration as part of an IST.

Tracking integration across phases

System integration would not be limited to new building construction. Renovations and expansion projects are increasingly more common as opportunities for greenfield construction become fewer. When demonstrating new equipment integrated with an existing system and as with any SOW, the CxP must and should clearly define client expectations.

Understanding construction phases, area turnover, and project milestones will enable the CxP to complete an SOW while minimizing impact on occupied spaces and potentially staff or occupants. This consideration for minimizing impact is emphasized in work associated with existing spaces, no more so than with healthcare. Consideration for patients' well-being is often imperative for a successful project, and that consideration is taken into account when developing the Cx plan and decidedly any IST effort.

Environmental conditions, such as summer and winter weather, may be considered when defining IST effort. If an IST intends to demonstrate building systems sequence of operations (SOO) by creating practical and “real world” scenarios, sequences of operation that are affected by seasonal conditions may benefit from opposed season testing. These opposed season tests may not be limited to HVAC equipment and reasonably be extended to include other equipment and systems.

For instance, performing an emergency generator required installation and acceptance load bank test during a winter season may provide artificial cooling, the results of which would not represent operation during possible worst-case and real-world scenarios, or summer season conditions. In this example, it may benefit the project to coordinate testing of the EPS during summer conditions, therefore demonstrating the integration of a building system or equipment with a season.

Envisioning the end goal

The commissioning process may be applied in various ways to similar equipment and systems. It is this variability and approach to commissioning that individualizes commissioning providers in an increasingly unified industry. The CxP’s ability to understand client goals, while remaining within the parameters of an agreed-upon SOW and incorporating those agreed-upon goals into the commissioning process often leads to better outcomes.

An IST would not be performed until the associated commissioning of equipment and systems is complete, therefore making the IST one of the last commissioning activities for the CxP and the Cx Team. The entire project team may benefit from considering the IST process as the final dress rehearsal for building systems before substantial completion and turnover to the owner.

The IST is unique in that it also signifies the culmination of the commissioning process. Successful ISTs establish that various materials, components, equipment, subsystems, and systems have been assembled into a unified network of systems. A building is more than just the sum of its parts. The interfaces and interactions among building systems introduce capabilities that are not possible with isolated system testing. With the IST process, the CxP can observe and assess operations and controls that reflect the owner’s intended real-world functionality for the facility.

When all systems perform in sync under real-world conditions, the IST provides more than just validation — it delivers assurance that the facility is prepared to operate safely, efficiently, and exactly as designed from day one.