Environmental Stress Screening (ESS) is a process which involves the application of one or more specific types of environmental stresses for the purpose of precipitating to failure, any latent, intermittent, or incipient defects or flaws which would cause product failure in the use environment. The stress may be applied in combination or in sequence on an accelerated basis but within product design limits. ESS detects manufacturing problems caused by poor workmanship or by faulty and/or marginal parts. It also identifies design problems if the design is inherently marginal and if qualification and engineering tests were too benign. ESS is based on the adjustment of stress screens in response to previously observed screening results to minimize Outgoing Defects. Stress screening is a closed-loop process and relies upon information from monitoring to improve processes and screens; that is, it is an iterative process. Only through this can Adaptive ESS be effective in terms of latent defect removal, and hence be cost effective.Stress screening should be monitored to a depth which ensures that all failure modes cause an ‘item failure’ indication. In this connection continuous monitoring of items during the screen should be undertaken where possible, since certain failures may only appear under stress and not at ambient conditions With no firm failure mechanism/mode information, Random Vibration followed by Thermal Cycling with few Power On/Off cycles is a good default condition. Screening should not stress the equipment such that fatigue failures are precipitated. Hilaire Ananda Perera has 39 Years of North American experience in Reliability/Maintainability/Safety Engineering https: //www.linkedin.com/in/hilaireperera/ - 2007 - Present: Reliability/Maintainability/Safety Consulting Engineer at Long Term Quality Assurance (LTQA), Markham, Ontario - 1983 - 2007: Reliability/Maintainability/Safety Engineer at Honeywell Aerospace, Mississauga, Ontario - 1981 - 1983: Reliability/Maintainability Engineer, Philips Electronics Ltd., Telecommunications Division, Scarborough, Ontario - 1977 - 1980: Design/Reliability Engineer, DAF Indal Ltd., Mississauga, Ontario - 1973 - 1976: Design Engineer, Stackpole Machinary Co., Scarborough, Ontario # Bachelor of Science Production Engineering (1972), University of Aston, Birmingham, England # Professional Engineer (P.Eng) 1976 to Present - Association of Professional Engineers of Ontario # Certified (1983 - 2007) Reliability Engineer - American Society for Quality # Honeywell Six Sigma Plus Green Belt Certified (2001), Honeywell Design For Six Sigma Certified (2003) # Allied-Signal Aerospace 1997 Growth Award. As a Senior Engineer applied mature engineering knowledge in planning and conducting reliability engineering and related product assurance projects. Emphasized the fact that reliability is the time-based concept of quality and reliability design is an iterative process that begins with specification of reliability goals consistent with cost and performance objectives. Introduced new approaches to achieve high product reliability. Performed to satisfy internal and external customers. Developed awareness of reliability within the organization. Served as a technical adviser on reliability issues. Assisted management in using reliability information to make. decisions for profitability. PUBLISHED PAPERS: ** Outgoing Reliability Assurance Using Chance Defective Exponential Model, AMMJ Mar 2015 ** An Introduction of Statistical Confidence Levels, AMMJ Sep 2014 ** Product Assurance Capability Quantified, Reliability Analysis Center (2Q2004) ** Adaptive ESS, Allied Signal Aerospace Company Technical Exchange Conference 25-26SEP1991 ** Optimum Cost Maintenance, Machine Design 20Jun1985 ** Reliability of Mechanical Parts, Machine Design 10Sep1987