Summary form only given. The development of wide software systems is an activity that consumes great quantities of time and resources. Even with the increase of the automation in the software development activities, the resources stay scarce. As a consequence of this, there is a big interest in the metrics of software due to its potential for a better, more efficient use of the resources. Tools help and assist in the planning and in the estimation of the complexity of the applications to develop during different stage of a process. We describe a technique to define metrics using the OMG (Object Management Group) standard specification. The semantic in each metrics is specified formally with OCL (Object Constraint Language) based on OMG metamodels. For their concrete specification, we establish a series of steps that allows define uniformly each metric in the different RUP models. Furthermore, the present paper shows the use of metrics defined using this technique and the relation between data obtained from the application of the metrics to thirteen object oriented systems. They encompass projects from the capture of requirements until its implementation, showing the metrics applied in different stage of the deployment.