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Engineering Systems Integration
expected to be delivered after integration and test). In the case of
entrepreneurs, the funding sources will nearly always insist on seeing an early prototype as a means of validation of the business
model, technical capability, and proof of market viability (as determined by testimonials from potential customers and users). At this
stage, the risk of not meeting the requirements is reduced, but not
eliminated.
• Development: The fifth stage describes the bulk of development.
Development personnel and support staff are hired or contracted,
resources are allocated, parts are procured, and units and subassemblies are built and tested.
• System integration: The sixth stage blends with the fifth stage as
development transforms parts into subassemblies that are integrated
into subsystems and then into the protosystem. The protosystem can
be accepted by the acquisition stakeholder as the deliverable product
or service.* The protosystem can also be a production prototype that
the customer and user should then contract to improve reliability,
engineer for production or manufacturing, or use as a system that
has limited use in a reasonably benign, not critical environment.
• Manufacturing or production: The seventh stage deals with the engineering of the protosystem to specify and deliver a manufacturable
end item product that satisfies stated requirements. Manufacturing
is the remaining test that the stakeholder requirements can be met
with more than a one-of-a-kind build. Batch or series construction
deals with using noncustom methods applied to problems that
would have been solved previously by hand-crafting custom solutions. Supplying a more standardized product or service further
reduces the risk that more than one product or service can be built to
satisfy stakeholder’s requirements.
• Purchasing: The sixth stage involves the offer to sale and the acceptance to buy. To purchase means to recognize the problem; to identify a need; to determine if the problem and the need are applicable
to current and future intentions of the acquiring organization; to
gather information to increase organizational knowledge; to negotiate; to agree on price, terms, acceptance, warranties, product support, maintenance; and delivery options and constraints. Purchasing
is the first test of the user’s acceptance of the product. That the product is believable and should be accepted by the buyer reduces the
risk that no one will need it.
* There is sometimes a concerted effort that builds only a few protosystems that have robust
properties and traits according to a set of requirements that imply use in an operational setting and environment. In those cases, the development effort must also include “design for
operations” which adds additional requirements and testing.