Abstract: When foreseeable maintenance is applied to pressure pipelines to prevent from the risk of fault and failure, information from multiple levels is required, such as the relationship of relative location among present pipeline status and data interval of design condition and material performance. In this paper, a calculation method based on expandable engineering is recommended, which is used to calculate relationship between the detected point (or aggregate of points) status on pipeline segment and the place value and degree of association of data interval or nest of intervals of design condition and material performance, that is the correlation function of intervals or nest of intervals on state point, which is used to analyze and create decision-making information, whether maintenance resource is required to set and when to set.