TABLE OF CONTENTS The intent of this appendix is not to provide complete risk algorithms to the reader, but rather to convey a sense of how modeling has been done in the past. Presentation of complete models would necessitate the inclusion of full documentation of all theory and rationale implicit in the model. That would take a book of this size for each comprehensive model evaluated. By presenting examples, it is hoped that the reader will gain confidence in setting up his or her own models. This confidence is gained through the knowledge that there is no magic approach that guarantees better results than any other. A good risk model will be firmly rooted in engineering concepts and consistent with experience and intuition. That is why there are so many similarities in the efforts of many different modelers examining many different systems at many different times for differing objectives. Beyond compatibility with engineering and experience, a model can take many forms especially in differing levels of detail and complexity.
The following discussions of two published pipeline risk models are extracted from preliminary work performed by Kiefner and Associates, Inc., on behalf of the Gas Research Institute [GRI]). Many other references on these models are available in the technical literature. These two were chosen as being fairly representative of many systems developed by consultants and by operating companies themselves.
Kiefner, J. F., Vieth, P. H., Orban, J. E., and Feder, P. I., Methods for Prioritizing Pipeline Maintenance and Rehabilitation, ...
