The Value of a 3rd Party in HIL Testing
Hardware in the Loop (HIL) testing continues to gain recognition as an effective verification method to improve the delivered quality for many of the integrated control systems found on a rig. The decision to implement HIL testing is usually based on a standard return on investment (ROI) question: Will the time and cost associated with implementing HIL testing return greater time and cost savings later in the project?
With a proper understanding of the unique role of HIL testing, and effective preparation and execution, the answer to this question is yes. Our experience has shown that with an effective and well-executed HIL test project, a significant number of control system defects can be discovered and corrected. Discovery and correction of defects at HIL test can be 10-100 times more cost effective than at commissioning, IAT, or operations. Additional benefits are gained as the commissioning and IAT are not delayed by the defects fixed at HIL test and can therefore stay focused on getting the systems installed and operational.
However, simply implementing an HIL test project does not guarantee these results. Correctly planning for and executing HIL testing requires very specific expertise – expertise that is often lacking on the project team. The participation of a qualified independent third party can close this expertise gap and significantly increase the value and effectiveness of the HIL project.
Over the last several years, Athens Group has provided independent third party expertise for HIL testing of integrated controls systems for drilling, well control and jacking equipment systems. In each case, there has been a quantifiable increase in the value and ROI of the HIL testing. Our experience has shown three areas of direct and quantifiable value:
1) Improved planning, preparation and program design
As a qualified third party, Athens Group brings an understanding of the unique role and value of HIL to the project team. HIL testing is an acceptance test methodology that is quite different from traditional FAT, Commissioning, and integrated acceptance testing. Quite often we hear “We don’t need HIL testing, we can cover it at commissioning or IAT.” This statement exposes a significant misunderstanding of the true purpose and value of the HIL test. HIL does not overlap these traditional test processes, and when properly executed, provides significant additional test coverage. Understanding the specific value and goals of HIL test, as opposed to other test milestones, is critical to achieving the maximum value.
The effectiveness of HIL testing, like any form of acceptance testing, can range from a simple, and relatively useless, demonstration of system features, to a highly effective proof of system compliance to end user requirements. All too often, we have seen HIL testing focused on the former. This type of green path operations-level testing ignores HIL’s unique ability to comprehensively test actuator and sensor failure modes. This is the single most useful information that HIL testing can provide when the system is tested as a whole and for integration with other equipment. Traditional FAT, commissioning and IAT do not provide this critical test coverage.
As a qualified independent third party, Athens Group can ensure that you understand the role of HIL and work with your HIL vendor to design an HIL test project that delivers the maximum ROI.
2) Maximized test effectiveness through the application of test engineering principles and expertise
The goal of any test methodology is to maximize test coverage given the constraints of time, the test method, and the physical tester capability. Test engineering is the specific discipline that delivers that goal. All too often, resources experts in other areas such as design, operations or maintenance, assume that they can recognize and implement an effective HIL test program. Likewise, team resources that have experience in FAT, commissioning or IAT often assume that experience is equally applicable to HIL testing.
HIL is unique in that it allows the safe and easy introduction of multiple sensor and actuator specific failure modes. Given this, HIL is significantly more dependent on the application of test engineering methods than traditional FAT, commissioning or IAT. These traditional tests are focused on operational functional defects. Instead, HIL provides the ability to focus on specific interface, actuator and sensor fault modes, which are often independent of operational functions.
Effectively implementing an HIL project requires an in-depth knowledge of the principles of test engineering, as well as a broad experience with similar systems in other environments or on other assets. It is understandably rare for FAT, Commissioning or IAT engineers to be versed on these principles or to have the requisite experience. Predictably, the result is an ineffective HIL test.
As a qualified independent third party, Athens Group brings the test engineering experience required to ensure that your test plan provides maximum fault mode test coverage that is specific to your requirements and operational procedures.
3) Increasing the effectiveness of the time and resources during the actual test execution
Time in simulator and on the tester is limited and all too often, the group executing the testing can lose focus, for example, to re-define requirements, re-design inadequately defined behaviors and debug problems. In addition, simulator defects frequently manifest as control systems defects, causing additional distractions. While these activities may often be useful, they are counterproductive to the goals of HIL test, which is the detection of control system defects. Having someone in the room, well versed in the specific value and implementation of test engineering and HIL can help keep the group focused and ensure that the testing is completed, all the necessary information is recorded, and the necessary results are achieved.
As a qualified independent third party, Athens Group can ensure that the limited time you have in the HIL test facility is optimized to provide maximum test effectiveness.
HIL testing has established itself as a cost-effective test method in a broad spectrum of industries and applications. However, like any test method, if misused it can become a costly and fruitless exercise. Before you consider any HIL test program, give careful consideration to the additional value of having a qualified independent third party like Athens Group representing you and your investment.
For additional information about Athens Group HIL testing, please email email@example.com.
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