META-MODEL

META-MODEL

The Meta-model, defined by the contribution of the University of Milan - Department of InformationTechnology - SESAR (Software Engineering Software Architecture Research Lab) represents the process(es) to be monitored, the measurements to be taken and the assessment frameworks to be used.
These three components have been designed independently, allowing to apply the same measurement framework to different processes, or to measure the same process according to different measurement frameworks. The interface between the process and the measurement modules is realized by the specification of measurable attributes of process activities and work products, needed by metrics. The interface between the measurement and the metrics modules is defined as a set of Key Performance Indicators (KPIs) based on measurements.
Computing process KPIs required the implementation of a series of specific extractors, that know which attributes to extract and where these attributes could be found in process and product definitions. Finally, all process metrics to be included in process reports are defined in terms of KPIs.

The meta-model is depicted in figure



We briefly describe the major meta-model modules: Process, Measurement, and Assessment.

Process module
The top element is the node Organization, which describes the whole organization and allows enterprise-wide measurements. It gathers all the Project nodes, which indicate a single project of the organization. Each project is associated to a specific development process model (waterfall, Agile, ..).

Measurement module
It is based on our reverse GQM (Goal-Question-Metric) approach and defines a generic framework exploitable to get measures from any development process.
The Information Need node is the container node that defines the need that drives all the measurement actions. For each information need there is a set of Measurable Concept nodes. These concepts drive the definition of the Measurable Attributes, which indicates the attributes to be measured in order to accomplish the analysis goals. The Measure node defines the structure of data retrieved during a measurement campaign. This node is directly connected to attributes and supplies raw data to KPI and Metric. Each node is specified by the nodes Scale Type and Unit, defining, respectively, the unit of measurement used and the type of scale adopted (nominal, ordinal, and so forth).
The monitoring indicators are defined in terms of KPIs (Key Process Indicator) and Metrics. Finally, the Metric class is in relation with the Threshold entity specifying the threshold values for each metric when needed for qualitative evaluations.

Assessment Module
The module simply defines a general assessment framework as CMMI or ISO 9001:2008.
This module allows a simple classification in terms of Category, Target, and Practice. The Practice node is connected with the Metric class in the Measurement module, highlighting the concept that the evaluation of a set of metrics could assess the real appraisal of the practices.