A Methodology for Mapping SysML Activity Diagram to Time Petri Net for
Requirement Validation of Embedded Real-Time Systems with Energy
Constraints
Ermeson Andrade, Paulo Maciel, Gustavo Callou, Bruno Nogueira
Federal University of Pernambuco (UFPE)
Informatics Center (CIn)
Recife, PE, Brazil
ecda, prmm, grac, bcsn@cin.ufpe.br
Abstract
In this paper we use the Activity diagram of the System
Modeling Language (SysML) in combination with the new
UML profile for Modeling and Analysis of Real-Time and
Embedded systems (MARTE) in order to validate functio-
nal, timing and low power requirements in early phases
of the embedded system development life-cycle. However,
SysML lacks a formal semantics and hence it is not possible
to apply, directly, mathematical techniques on SysML mo-
dels for system validation. Thus, a novel approach for auto-
matic translation of SysML Activity diagram into Time Petri
Net with Energy constraints (ETPN) is proposed. In order to
depict the practical usability of the proposed method, a case
study is presented, namely, pulse-oximeter. Besides, the es-
timates obtained (execution time and energy consumption)
from the model are 95% close to the respective measures
obtained from the real hardware platform.
1 Introduction
Embedded systems that have timing constraints are clas-
sified as real-time systems. In these systems, not only the
logical results of computations are important, but also the
time instant in which they are obtained. Hard real-time sys-
tems are those whose the respective timing constraints must
be met at all cost, since violation might be catastrophic.
Hence, time predictability is an essential issue. In additio-
nal, the widespread expansion of mobile devices market has
forced embedded systems companies to deal with several
additional challenges in order to provide complex systems
in this market niche. One of the most important challen-
ges is related to energy consumption, since portable devices
generally rely on constrained energy sources (e.g. battery).
As consequence, early estimation of the energy consump-
tion can provide important insights to the designer about
the battery lifetime as well as parts of the application that
needs optimization.
In addition, heterogeneity and complexity growth of the
Embedded Real-Time Systems (ERTS) require interdisci-
plinary approaches in development processes embracing
software engineering, mechanics, electric and electronics
areas. Accordingly, a modeling language, called SysML
[11], has been specified by OMG (Object Management
Group) which supports the specification, analysis, design,
verification and validation of a broad range of complex sys-
tems. These systems may include hardware, software, in-
formation, processes, personnel, and facilities. However,
SysML does not provide support for quantitative notations.
Quantitative notations are especially important when mode-
ling ERTS. Hence, we consider the SysML in combination
with MARTE [1] as specification language for the design of
ERTS. MARTE foster the construction of models that may
be used to make quantitative predictions regarding real-time
and embedded features of systems taking into account both
hardware and software characteristics [1].
SysML is composed of several diagram types (use case,
activity, sequence and so on). Activity Diagram (AD) [11]
is adopted in this work due to its suitable characteristics for
modeling requirement when dealing with real-time systems.
The SysML-ADs are used to model the dynamic system as-
pects.
This work aims to depict the mapping of SysML-AD into
an ETPN [13] in order to estimate the energy consumption
and execution time of ERTS. The execution time and energy
consumption constraints are represented as MARTE profile
annotations. The ETPN model is generated by a mapping
process, after that, the model is evaluated for calculating
the best and worst path execution time and the respective
energy consumption. Moreover, the ETPN model is also
adopted for qualitative analysis and verification.
!009 Third International Conference on Digital Society
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DOI 10.110!/ICDS.200!.1!
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