Software measurement is a key process for software process improvement. Measurement provides organizations with the objective information they need to make informed decisions that impact their business performance. Nowadays, there are several process quality models and standards that point out the importance of software measurement, such as CMMI. Unfortunately, the vocabulary used by those models concerning software measurement is diverse. This leads to misunderstanding and problems related to the jointly use of different standards. In this paper, we present a fragment of a Software Measurement Ontology (SMO) with focus on measurement at high maturity levels. In order to establish a basic conceptualization regarding this domain, the Unified Foundational Ontology was used to ground SMO.