The Grade II Listed, regency building that houses the headquarters of Mass Consultants near Cambridge may appear to be as far removed as is possible from the cutting edge technology development in which the company excels. However, there is one similarity between Mass Consultants' activities and its building: elegant design.

Founded in 1983, Mass Consultants is a Systems House specializing in the concept development, design, build, integration and support of high technology equipment. With individual groups focussing on systems engineering, software development and consultancy, Mass has an impressive set of credentials both in military and commercial fields. Customers include British Aerospace, GEC-Marconi, GKN, Dowty, Ford, McLaren, Cable & Wireless, GPT, Vodafone, Panasonic and the Civil Aviation Authority.

The Challenge

When BAe Military Aircraft commissioned an Electronic Warfare Test Facility (EWTF) to evaluate the electronic counter measures (ECM) of its aircraft, the company set a number of highly challenging requirements. The EWTF is a full aircraft test chamber that is designed to test the performance of Eurofighter's Defensive Aids Sub System (DASS). The aircraft is suspended in a chamber and immersed in a simulated threat environment. Simulated enemy radar and missile tracking systems bombard the Eurofighter at random and the EWTF monitors and analyses the responses of the DASS as well as the threat environment.

The scale and complexity of the ECM generated by the DASS prohibited capturing all the data and post-processing it. Consequently, the Digital Signal Analysis System (DSAS) a focal part of the EWTF data acquisition and measurement systems needed to capture and process the data in real-time.

Developing this system was the task British Aerospace set Mass Consultants.

A Real-time Solution

To manage the development of this complex system, Mass Consultants' Design Authority Paul Field decided to adopt a formal analysis and design methodology. This would help ensure that the requirements of the EWTF DSAS were fully addressed and provide accurate and consistent design documentation - essential for effective coordination of the development team and for maintenance of the delivered system and effective communication between Mass and its customer, BAe.

Paul is familiar with structured methods, such as Yourdon, and had used OO analysis and design tools previously, including Select Enterprise. But, because the project required the integration of software with specialized hardware, he needed a tool that would enable him to analyze performance requirements in the design and to understand design implications of both the hardware and software architecture of the system. He selected ARTiSAN's Real-time Studio to support the development of the EWTF because of ARTiSAN's specific modeling capabilities for real-time systems and support of the Unified Modeling Language (UML).

"We liked the system focus of Real-time Studio rather than basic application software focus found in other tools and the fact that ARTiSAN understood the issues involved in real-time development," comments Field. "What was impressive about Real-time Studio was that it captures the whole system. You can look at your design from the top level and then drop down into the individual component parts. Being able to capture all aspects of a system in one model is invaluable."

The Team and System

A four man software team was assigned to the project — two working on design with the modeling tool and two on the test system. They were supplemented by a signal processing specialist for certain aspects of the project.

The hardware selected was a VMEbus system comprising two Motorola MVME3600 boards, each featuring a 300MHz PowerPC 604 processor, in an EMC-screened Vero VMEbus enclosure. The software was developed in C++ and runs on top of VxWorks, a real-time operating system from Wind River Systems.

Data acquisition tasks are managed by one processor while the other handles data analysis and communications with the control system. The system undertakes two forms of analysis: Frequency domain analysis measuring signal power and bandwidth and time domain analysis measuring pulse width, amplitude and frequency.

Starting on their first project with Real-time Studio was simple, says Paul Field: "Because of my OO and UML experience, I had no problems picking it up. The other engineer on the software design team had not used either OO or UML previously but, with some CASE tool experience and familiarity with OO concepts, he also picked up Real-time Studio easily."

Benefits of Real-time Studio

Mass Consultants found many aspects of Real-time Studio that aided the project's development. "Being able to represent the physical hardware architecture of the system in a common notation along with the conceptual software design elements certainly helped the team communicate ideas," says Field. "The concurrency diagram is excellent for showing the operating system interfaces, together with which tasks talk to each other and their synchronization."

The document generation utility was used to aid production of the system and software design specifications in the style and format required by BAe. Because all the descriptions, including classes, attributes and operations, are stored within the tool there is no need to duplicate this information separately in order to create documentation. Mass' engineers simply designed within the tool and then hit a button to extract all the information that had been entered.

Another productivity benefit Field experienced was that 10 percent of the overall code production time was saved through the use of Real-time Studio's code synchronizer, which provides code generation and reverse engineering of the design.

As the project progressed and the company became increasingly impressed with Real-time Studio, Mass decided to train more of its engineers in the use of the tools and contracted ARTiSAN to provide on-site training for a further 12 engineers on the use of OO analysis and design in real-time system development. There was a positive response from all who attended, and team communication has been enhanced by the ability to discuss ideas in concepts supported by Real-time Studio.

According to Field: "We now have a common mechanism for expressing design concepts, which aids the review process. The course certainly got people talking to each other about design and notation."

Project Management

Mass Consultants started the British Aerospace DSAS project (its first with Real-time Studio) in January 1998. Acceptance testing began in February 1999 - on schedule and within budget.

Andy Lipinski, Programmes Director at Mass and the man responsible for ensuring that all projects come in on time and within budget, has no doubt about the value of adopting Real-time Studio. "We chose Real-time Studio for a single trial project and used it for all stages from requirements capture through to code generation. It was easy to adopt and did everything we wanted," he states.

As for the future, Paul Field plans to use Real-time Studio on his next project and it is already being used on the development of a radio modem. Furthermore, a number of existing designs - including an axle/sub-frame alignment system for Jaguar cars - are being migrated to Real-time Studio for ease of maintenance and future development.

With more Mass engineers scheduled to attend Real-time Studio training courses, the trial can be said to have been a great success.