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- Flying Object: European Air Navigation System Gets Overhaul
-
- As air traffic increases in Europe, navigation and safety are becoming
- critical issues. As a result, the European Community is revamping its
- air-traffic safety systems.
-
- Eurocontrol is an independent European organization overseeing air
- navigation safety. It consists of 16 member states that have joined
- forces to develop new systems anci to gradually upgrade existing air-
- traffic navigation systems throughout Europe. There are five Eurocontrol
- centers in Europe, each one respon- sible for clifferent activities for
- the project.
-
- At the Eurocontrol Experimental Center south of Paris, developers are
- working on collision-avoidance softwaire and a mathematical simulator
- using object-oriented technology, the Booch method, Rational Rose, and
- Ada.
-
- One of these projects, RAMS (Re- organized ATC Mathematical Simulator),
- is a simulator developed and used in-house by the Eurocontrol
- Experimental Center. RAMS is also used by external groups, such as
- national aviation organizations. The RAMS program simulates different
- air patterns, enabling researchers to study a new section of air space
- and new monitoring procedures.
-
- The RAMS project consists of about 100,000 lines of code and required 15
- man-years of development work.
-
- The second project, called Airborne Collision Avoidance System (ACAS), is
- a safety-system simulator that consists of more than 40,000 lines of Ada
- code, required six man- years of development work, and was completed two
- months ahead of schedule.
-
- A methodological approach
-
- For each of these projects, the development teams adopted an iterative
- approach and the Ada programming language. For the design phase,
- Eurocontrol used the Booch method and Rational Rose. By using an
- object-oriented design approach, developers were abIe to take full
- advantage of many of the features and benefits of the Ada language,
- including abstraction and information hiding.
-
- "Once we had decided to take an iterative, object-oriented approach to
- the project, we needed to select an effective methodology," explains
- Michael Lott, head of the software- engineering unit at Eurocontrol. "We
- needed a method that was well defined by a recognized expert. This
- method also had to be supported by several tools. We selected the Booch
- method and Rational Rose based on these criteria."
-
- The primary reasons for selecting an iterative, object-oriented approach
- were maintainability, flexibility, and reusability of the software over
- its lifetime, which Eurocontrol estimates to be from 12 to 15 years.
-
- "Many of our projects are maintained over long periods of time and are
- modified regularly," says Lott. "For example, our real-time simulator
- needs to be modified for most specific simulations, and the software
- must be adaptable. With object- oriented technology, we are able to
- simplify this process."
-
- (reprinted by permission from Rational Watch, Summer 1994)
-