Subsystem Hazard Analysis Examine subsystems to determine how their -Normal performance Operational degradation Functional failure -Unintended function Inadvertent function(proper function but at wrong time or in wrong order)

Builds on PHA as a foundation (expands PHA) Considers system as a whole and identifies how system operation nterfaces and interactions between subsystems interface and interactions between system and operators component failures and normal (correct) behavior

The designers had no intention of ignoring the human factor. But the technological questions became so overwhelming that they commanded the most attention

Unfortunately, everyone had forgotten why the branch came off the top of the main and nobody realized that this was important

Hazard log Information System, subsystem, unit Description Cause s Possible effects, effect on system Category(hazard level --probability and severity) Design constraints

People, not things, are the cause of accidents environment Removing any of dominoes will break sequence but said third was easiest to remove Focus on single causes Chain-of-Events Models Explain accidents in terms of multiple events, sequenced

Interactive Complexity Complexity is a moving target The underlying factor is intellectual manageability 1. A\simple\system has a small number of unknowns in its nteractions within the system and with its environment

Progress reports are essential Often part of Provide precise scheduled deliverables technical description Maintain contact with of work as project funding Sources develops and/or industry partners, and changes

Introduction A primary goal of your efforts in this course will be to gather empirical data so as to prove(or disprove) your hypothesis Typically the data that you gather will not directly satisfy this goal Rather, it will be necessary to \reduce\the data. to put it into an appropriate form, so that you can

Quick review 1. Show the reader what s/he needs to see 2. Plan the sequence and directionality 3. Think about the focal point of the graphic 4. Integrate labels units of measurement. and information