Database Reference
In-Depth Information
Concurrent Engineering
Concurrent engineering (British English: simultaneous engineering ) is a
workflow that, instead of working sequentially through stages, carries out
a number of tasks in parallel. For example, it might involve starting tool
design as soon as the detailed design has started, even before the detailed
designs of the product are finished; or it might entail starting on detailed
design of solid models before the concept design of surface models is com-
plete. Although this does not necessarily reduce the amount of manpower
required for a project, as more changes are required due to the incomplete
and changing information, it does drastically reduce lead times and thus
time to market.
Feature-based CAD systems have for many years allowed the simultane-
ous work on 3-D solid models and the 2-D drawings by means of two sepa-
rate files, with the drawing looking at the data in the solid model; when the
model changes, the drawing will associatively update. Some CAD pack-
ages also allow associative copying of geometry between files. This allows,
for example, the copying of a part design into the files used by the tooling
designer. The manufacturing engineer can then start work on tools before
the final design freeze; up to that point, when a design changes size or
shape, the tool geometry will then update. Concurrent engineering also has
the added benefit of providing better and more immediate communication
between departments, reducing the chance of costly, late design changes. It
adopts a problem-prevention method as compared to the problem-solving
and redesigning method of traditional sequential engineering.
Bottom-Up Design
Bottom-up design occurs where the definition of 3-D models of a product
starts with the construction of individual components. These are then vir-
tually brought together in subassemblies of more than one level until the
full product is digitally defined. This is sometimes known as the review
structure showing what the product will look like. The BOM contains all
of the physical (solid) components; it may (but not necessarily) contain
other items required for the final-product BOM such as paint, glue, oil,
and other materials commonly described as bulk items. Bulk items typi-
cally have mass and quantities, but they are not usually modeled with
geomet r y.
Search WWH ::




Custom Search