The ISO 9126 quality model is a 4-part suite of documents presenting 10 characteristics of the quality of software products, 27 subcharacteristics, and an inventory of more than 250 derived measures proposed to quantify these quality characteristics and subcharacteristics. However, these measures are presented only at a fairly abstract level as formulae composed from a set of 80 base measures. As the base measures themselves lack detailed descriptions, including the attributes they are attempting to measure, they are highly susceptible to individual interpretation. Improving the design of the 80 base measures is a daunting task. The ISO 9126 standard is currently under revision by an ISO working group (ISO/IEC JTC1/SC7 WG6), and this paper proposes a process to determine which of these base measures should be improved in the timeliest fashion.