An apparatus and method for securing a tubular within another tubular or borehole, creating a seal across an annulus in a well bore, and centralising or anchoring tubing within a wellbore. A system includes a quantifying component that generates, based on a distance map, a signal indicative of a quantification of characteristic of a lumen of a tubular structure of interest over a pre-determined extent of the tubular structure of interest represented in volumetric imaging data. The external portion prevents insertion of the circuit breaker into a breaker box closer than the distances defining the space. A projection matrix for calculating the risk assessment value is calculated using the calculated M-dimensional feature vector.