| DEX (D002):— fault_states | Date: 2006/06/14 12:04:06 Revision: 1.22 |
An application activity model (AAM) is provided in AP239 as an aid to understanding the scope and information requirements defined in AP239. The model is presented as a set of figures that contain the activity diagrams and a set of definitions of the activities and their data.
This DEX will support a subset of the activities and data flows. These are highlighted in yellow in the subsequent figures.
Activities and data flows that are out of scope of AP239 are marked with an asterisk.
The following terms are used in the application activity model.
action to determine the potential faults or other degraded states that the support solution shall address, including cause, effect and other relationships between them, as applicable to each product function requiring support, part, and attachment slot
NOTE The ARM of this part of ISO 10303 defines the concept of predicted states of a product and this concept is appropriate for representation of faults. A product can be either a part of a function. The sequences of individual faults involved in a failure can be represented by the relationship between predicted states.
set of assured and related information used to develop and deliver support for a product in focus, including feedback from using and supporting the product over its life cycle
NOTE Related information includes records of the history of the usage or support of realized products, design and support analysis results and reasons why decisions were taken. Such information includes design and failure analysis records, logistic support analyses, running hours, environment descriptions, operating profiles; test results, records of maintenance activities, resources used, and faults found plus any other content deemed relevant to life cycle support.
identification and description of each potential fault or other degraded state that can affect each part, function or usage occurrence in each operating environment, including cause, effect or other relationships between relevant states
NOTE The product functions can be represented by a functional breakdown. Faults can be defined as product states.
The Fault State DEX deals with how a product can or may degrade in its functions or change the value of its properties. It is usual for the set of fault states to be derived from a formal analysis process such as Failure Modes and Effects Analysis (FMEA).
A set of basic definitions:
The information exchanged by this Dex is the set of "potential faults and relationships" produced as a result of the PLCS AAM activity A2224 "define potential faults".
NOTE The product functions may be represented by a functional_breakdown. Faults may be defined using the state_definition module.
EXAMPLE A bicycle has a breaking function. During a ride one could detect that the ability to decelerate or stop the bicycle as needed is no longer available, hence a failure has occurred. The bike is then in a fault state. There could be more than one sequence of events leading to this fault state. These are known as failure modes. Possible examples of failure modes are broken break cable or break block worn beyond limits.
