Thesis defense of Stéphanie Gatti

February 12th, 2014 - Thesis defense of Stéphanie Gatti on Step-wise Approach for Integrating QoS throughout Software Development Process

In critical domains such as avionics, railways or automotive, to
certify a system, it is required to demonstrate that it achieves its
function, with respect to specified timing requirements. Indeed,
longer-than-predicted function computing can make data erroneous,
leading potentially to endanger people lives. Today, most
approaches propose to ensure these Quality of Service requirements
at platform level, e.g., through deterministic bandwidth,
static time slots allocation and predefined scheduling. These constraints
ensure applications can’t overpass allocated time slots;
applications are then fed with requirements decoupled to their
functionality. However, it shall be possible to certify timing requirements,
dedicated to an application. Hence, guarantees at
platform-level are not sufficient anymore. It should be possible
to take into account these requirements from the stage of application
design. Today, most of existing approaches in this domain,
focus on supporting QoS at individual stages of the software
development process, preventing requirements traceability.

This thesis proposes a design-driven approach to supporting
QoS throughout software development process, integrated in a
tool-based methodology, namely DiaSuite. The QoS extension
enriches the DiaSpec design language, with the capability to
instantiate QoS requirements onto software components. A runtime
execution support to monitoring these timing requirements,
is then generated, directly from the specification. This thesis
uniformly integrates timing concepts with error ones, around
DiaSuite methodology, to propose a supervision layer that could
lead to application reconfiguration in case of QoS contract violation.
Contributions of this thesis are evaluated through respect
of coherence and conformance critera, illustrated through a case
study in avionics.