A key requirement for nanomanufacturing is maintaining acceptable traceability of measurements performed to determine size. Given that properties and functionality at the nanoscale are governed by absolute size, maintaining the traceability of dimensional measurements of nanoscale devices is crucial to the success of nanomanufacturing. There are various strategies for introducing traceability into the nanomanufacturing environment. Some involve first principles, but most entail the use of calibrated artifacts. In an environment where different types of products are manufactured, it is challenging to maintain traceability across different products mix. In this paper, we present some of the work we have done in developing methods to track the traceability of dimensional measurements performed in a wafer fabrication facility. We combine the concepts of reference measurement system, measurement assurance, and metrological timelines to ensure that traceability is maintained through a series of measurements that involve different instruments and product mixes, spanning a four-year period. We show how to use knowledge of process-induced and instrument systematic errors, among others, to ensure that the traceability of the measurements is maintained.