Systems engineering approach to chemical biological and radiological detection system design

The ability to design effective detection systems is critical to the development of systems to protect against and respond to chemical, biological, and radiological (CBR) attacks. Unfortunately, there are numerous examples of CBR detection systems being designed “in a vacuum,” without full consideration of threat and vulnerability assessments, or the proposed protection strategy and response plans that the detection system must support. The potential negative effects of this approach include systems that are excessively costly in the best case, and systems that fail to deliver the required detection performance while providing a false sense of security in the worst case. The solution to this problem is the application of systems engineering principles. As with any system, the critical foundation for the system design is requirements development. Requirements for CBR detection systems include, but are not limited to, the spectrum of threats to be detected, the required sensitivity and speed of detection for each threat, the allowable false alarm and false negative rates, and operations and maintenance (O&M) needs. The requirements form the basis of system architecture and component selection, and allow trade studies that support an optimal system design. The process continues through detailed system design and integration, and culminates with system commissioning, verification and validation, and O&M planning. This paper presents Battelle's systems engineering approach to CBR detection system design and discusses several aspects of detection systems including: • Similarities and differences between chemical, biological, and radiological detection systems • Difference in requirements for “detect to warn”, “detect to protect”, and “detect to treat” strategies • Detector selection options • Architecture options such as sampling systems to cost-effectively increase coverage or response speed, and use of “orthogonal” detectors or trigger and confirmatory detectors for false alarm reduction Also discussed are the role of modeling in requirements development and system design, as well as the importance of commissioning and testing to effective detection system performance.