In a perfect world, one would always know the answer to that question. Unfortunately, nobody works in a perfect world. This paper will explore statistical techniques used to look for deviations in metrics that are due to assignable causes as opposed to the period to period variation that is normally present. Hypothesis Testing, Statistical Process Control, Multivariate Adaptive Statistical Filt...

The goal of engineering process control (EPC) is to minimize variability by adjusting some manipulative process variables. The goal of statistical process control (SPC) is to reduce variability by monitoring and eliminating assignable causes of variation. As suggested by Box and Kramer and others, it is possible to reduce both special cause and common cause variations by integrating EPC and SPC...

The basic control chart consists of sampling from a process over time and charting process measurements. For as long as the measurements fall inside control limits (L), the process is considered in-control. In feed production, it is customary to set the control limits at two standard deviations. This practice does not consider the probability of both Type I and Type II errors in addition to all...

In this paper a sensitivity analysis for optimal solutions of the wellknown Duncan’s model is proposed to misspecification in the cost parameters. The analysis is performed both in the continuous case, i.e. when the production process continues in operation while searches for the assignable cause after a signal are made, and in the more realistic discontinuous case, i.e. when a signal causes a ...

Runtime assertion checking is useful for debugging programs and specifications. Existing tools check invariants as well as method preand postconditions, but mostly ignore assignable (or modifies) clauses, which specify the heap locations a method is allowed to assign to. A way to abstract from implementation details is to specify assignable clauses using datagroups, which represent sets of conc...

The human-machine function allocation (HFA) strategy of manned submersibles is an important factor that affects the reliability oceanauts. However, uncertainty HFA makes its optimization very complicated. To this end, a non-cooperative game-based method proposed, which transforms multi-objective model mental workload and situation awareness (SA) under into game forms mapping relationship. Menta...

In batch manufacturing processes, the total process variation is generally decomposed into batchby-batch variation and within-batch variation. Since different variation components may be caused by different sources, separation, testing, and estimation of each variance component are essential to the process improvement. Most of the previous SPC research emphasized reducing variations due to assi...

Modern aircraft flight control relies on a complex network of interacting systems. These systems are safety critical systems, since a failure could have catastrophic consequences. It is therefore necessary to detect and isolate faults in aircraft control system components such as actuators or sensors before the fault is allowed to cause a system failure. Such detection and isolation could poten...