The availability of buried pipelines is a function of preventive and corrective maintenance.

Gasunie's current pipeline maintenance regime was evaluated to determine how far incident frequency and cost could be optimised. The study revealed that closer attention needed to be paid in particular to the monitoring of unreported excavation activities. After assessing the effectiveness of the surveying procedure, three other alternatives were considered. Of these, fortnightly aerial surveys proved to be the most efficient. With a view to limiting the consequences of an accidental escape of gas, a study was made of available detection systems and the desirability of combining such a system with remote valve operation. In Gasunie's opinion, direct combination is not feasible at this stage, but future developments in this field will be given the required attention.

The availability analysis methods as commonly used did not generate the most substantial contribution in this project. The findings of this study are mainly the outcome of structured thinking, data analysis and discussion.