Despite the best intentions of legislators, Europe’s defence
industry must respond to the challenges imposed by the economic
realities of the global drive toward lead-free electronics.
Military equipment is one of the product categories exempted in the
RoHS and WEEE Directives but, in reality, the widespread use of
COTS components in military equipment is forcing defence
contractors into the lead-free front line.
This is because commercial component manufacturers cannot
economically convert their entire catalogue to lead-free, and are
instead withdrawing some components from the market. Most of these
are now superseded for commercial applications, but the long-term
support requirements for military products can spell problems for
defence contractors. All components, from passives to
semiconductors to LCDs, are affected.
Europe’s defence contractors, therefore, may be forced to divert
their design teams into time-consuming sustaining engineering
tasks. This will naturally divert resource away from R&D,
putting those businesses at risk of falling behind competitors
operating in other territories.
After the last time buy
The first response by a contractor upon notification of a planned
component obsolescence is to consider buying sufficient stock to
satisfy foreseeable requirements. This may not always be
possible.
For example, if the component is an old design, last time buy
stocks may not be large enough. Another risk is that contractors
who infrequently buy small numbers of a particular component may
not even be informed of the obsolescence. This can be a significant
problem for defence contractors who are usually required by
government agencies to support equipment for up to 25 years and may
wish to provide spares and repair services for even longer.
When manufacturers’ inventories, buffer stocks and grey sources
have all been exhausted, there is usually no option but to redesign
the assembly to use a more readily available alternative or a
lead-free replacement.
This may entail designing-in an equivalent component or a more
labour-intensive route, such as designing a functionally equivalent
circuit. In either case, these are non-core activities for the
contractor’s engineers, which do not enhance the organisation’s
technology position. This makes it an ideal activity to outsource
to a design services partner.
Outsource with care
Changes to equipment that has already been approved by the
accepting body in a particular form are not undertaken lightly.
Indeed, a good case must be presented to show that the changes are
necessary and there is no reasonable alternative.
A partner organisation, such as a design services specialist,
taking on the responsibility for updating the design in response to
component obsolescence should be familiar with the procedures
involved and the supporting information required.
For example, in the first instance it is necessary to analyse the
product and assess the relative risks of changing or not changing
the design. Any changes must first be proposed to the accepting
body, with a clear explanation of the scope of the changes as well
as evidence there will be no impact on the fitness for purpose of
the equipment.
Moreover, the complexity and cost of the approvals process can be
minimised if it can be proved that the changes will have no
practical bearing on the existing approvals already held for the
equipment. Performing a detailed analysis of the changes required,
including calculating any impact on the equipment as a whole, can
reduce the burden of re-approval by instead allowing the existing
approval to be updated.
It is also important that the selected partner should be able to
interact seamlessly with the established quality procedures. The
advantage of this is the outsourced work and supporting
documentation can be absorbed directly, allowing the original
vendor approvals issued by the accepting body to cover the new
design work.
Partners and project management
In addition
to familiarity with the applicable approval processes, the key to
successful sustaining engineering is to establish control over all
aspects of the challenge from the beginning.
This includes a comprehensive assessment of the overall equipment
set, taking into account factors including the operating
environment, power supply requirements, weight, dimensions and
external interfaces, in addition to the functional specifications.
A thorough analysis of the component being replaced and all aspects
of its contribution to the function and characteristics of the end
equipment is also critical to ensuring that replacement circuitry
does not compromise the fit, form and function of the end
product.
It is also important to identify any implications for the system
software. Software changes may be required, for example if a
slightly dissimilar unit replaces a hardware peripheral such as an
LCD panel.
Any necessary changes to software must be preceded by detailed
analysis to determine the function of the routine involved and to
identify all other routines affected. This task is naturally faster
and less complex if the system software is fundamentally of good
quality.
Performing a comprehensive analysis effectively builds into a
specification that can be used as a reference to ensure that the
new routine will behave identically as far as the remainder of the
system is concerned.
Get help with lead-free
Europe’s defence industry, despite the exemptions from RoHS and
WEEE legislation, must nevertheless respond to the changes
occurring in the wider electronics industry. Offloading some of
this burden, such as designing-out obsoleted COTS components, to a
specialist partner makes strategic and economic sense. It can also
help to manage engineering resources in the immediate term.
However, while it is not usually necessary for the partner
organisation to hold explicit defence industry approvals, it is
more important to ensure compatibility in terms of procedures and
standards so the new work can be absorbed directly into the ongoing
equipment support project.
As always, knowing what to look for in a potential design services
partner is key to achieving the full economic and competitive
benefits of outsourcing.
Ken Hall is technical director at Triteq