Cost of NOT Having a Sensor

Abstract

Appropriate incorporation of sensors in high-value engineering systems is a precondition for effective automatic control, safety, economic operation and sustainment. An inadequate set of sensors can increase workload on operator, compromise safety, and affect maintenance and optimal utilization. From the viewpoint of troubleshooting and maintenance, lack of sensors may result in ambiguities in diagnostic outcomes and hence higher Retest-OKs, necessitate additional manual testing, require higher level of expertknowledge for problem identification and troubleshooting, and fail to provide ahead-of-time indication for maintenance-requirement. Operation and Support (O&S) related activities are the major cost drivers over the life-cycle of high-value engineering systems, and all of the above mentioned issue, likely present due to inadequate set of sensors, ramp-up the system’s O&S costs. However, introduction of a sensor adds to system complexity, cost, weight, power consumption, and may require additional communication and processing capabilities. Therefore, addition of a sensor should be justified by weighing the costs of “having” vs. “NOT having” the sensor. Qualtech Systems, Inc. (QSI) has developed techniques and incorporated those into TEAMS (Testability Engineering and Maintenance System) toolset to perform a cost vs. benefit analysis for complex engineering systems with different sensor configurations. The techniques can also identify the optimal sensor suite that minimizes O&S cost over the lifetime of a system, while satisfying user defined cost, performance, and operational constraints. This paper provides a detailed account of the “Cost of not having a Sensor” analysis and how it aids in developing appropriate criteria and a business case for including a sensor or not. This paper also extends the above analysis into the development of a sensor optimization scheme with some real-world use-cases highlighting its utility.