Aviation program overruns and problems with new aircraft are more common than desired, prompting some calls for a new approach to aircraft designs. That's leading some design tool suppliers to call for changes in the way aircraft development programs are structured.
One technique is to take a broader view of the many facets of design, examining all aspects as a whole. Every subsystem must be designed with an eye toward compatibility with all other components in the plane.
“Holistic design used to be optional, but today it’s truly necessary,” said Martin O'Brien, General Manager at Mentor Graphics. “Something has to change. Almost every major program in aerospace suffers from overruns, often by 50 to 100% of estimates.”
This holistic design approach brings many benefits, said O’Brien and other speakers at a recent Mentor Integrated Electrical Solutions Forum on aircraft design. When design teams communicate with each other and consider factors including integration and manufacturing, there will be fewer faults and they will be discovered earlier.
“Most of the really big problems arise when system integrators put disparate products together, like boards and software,” said Walden Rhines, CEO of EDA (electronic design automation) vendor Mentor Graphics. “Companies want ways to find faults earlier when the cost of fixing them is low.’’
Other tool providers noted that software should make it easier to alter designs. This will help reduce problems while making it easier to enhance performance or pricing.
“System engineering programs need to be optimized for change, not stability,” said Barclay Brown, Global Solution Executive for Systems Engineering for IBM Rational. “Often design teams get into a project and see ways to make big improvements if they make some changes. But they can’t do it because the designs are set in stone.”
Improving communications between the many design teams will be one of the biggest challenges facing tool providers and aircraft developers. It’s still difficult to ensure that engineers involved in disparate fields such as hardware and software mechanics know how their sections mesh with other parts of the project.
“Multidiscipline collaboration often occurs ad hoc, which leads to a failure to control costs, time frames, and even performance,” O'Brien said. “There are language barriers when hardware, software, and mechanical engineers work together within one company, let alone when they start talking to people at other companies.”
One important aspect of this is to pull together the myriad tools used to design modern aircraft. Several commercial and proprietary software tools are used by the many design specialists who participate in the overall aircraft development program.
“When you look at the number of design tools used for large products like aircraft and autos, you’re literally looking at thousands of design tools,” O'Brien said. “Each domain has its own in-house tools for verifying what they have done. When you put three platforms together after they’ve each been verified, you’ve got a new challenge for verification.”
Those tools must also ensure that engineers and programmers are working with data that is constantly updated. Aircraft design programs are still plagued by errors that occur when one team changes something without the knowledge of a related design team.
“The industry needs more deterministic tools to liberate engineers at the platform level,” O'Brien said.
Design tools must also make it easier to reuse existing elements. If these components were designed using the same rules used for new components, new and old sections should interconnect with minimal issues.
“There’s a lot of reusable content within every company,” O'Brien said. “Creating transitions so it can be used in different platforms is a major benefit. If companies use rule-based design built on constraints set by the company, they will have fewer problems when platforms come together.”