Reengineering real-time software systems

The problem this thesis solves is how to reengineer existing real- time applications implemented without software engineering (SE) attributes; with poor modularity and robustness, and that are difficult to read and maintain. The real-time system chosen for this study was the Model-based Mobile robot Language (MML) used on the Yamabico- 11 mobile robot, which was implemented without SE attributes. The approach taken was reengineering MML with a focus on improving modifiability while preserving functionality. First we developed a systematic plan using manual static analysis, then we incrementally reengineered the application with thorough system-level testing. Code review was used to locate and remove dead code, and synonymous and redundant variables and functions (improving modifiability, readability and robustness). Call-hierarchy tracing was used to gain explicit module restructuring insight for tighter cohesion (improving modifiability, modularity, and readability). Global-variable tracing was used to improve module coupling by localizing and minimizing global variables (improving modularity, readability, and robustness). The results were as follows: A method for applying SE to existing real-time applications after- the-fact called 'Reengineering Real-Time Software Systems' was developed, which improves modifiability, modularity, robustness and readability. MML now has improved modularity and robustness, and is easier to read and maintain.

Department dc:contributor.department

Department of Computer Science

Grantor dc:publisher

Monterey, California. Naval Postgraduate School

Year dc:date.issued

1993

Author dc:creator

• Scott, Randall C.

Advisor dc:contributor.advisor

• Kanayama, Yutaka

Statement dc:rights

• This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10945/39996

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/39996