ADMS 4245 Lecture Notes - Injection Moulding
CH 12 – Prototyping
•Industrial Designers produce prototypes as their concepts
•Engineers prototype a design
•Software developers write prototype programs
Prototype: it is an approximation of the product along one or more dimensions of
Types of Prototypes:
it can be classified in 2 dimensions: 1) Physical and analytical 2)comprehensive and
•1) Physical: They are tangible artifacts crated to approximate the product
oAnalytical: they represent the product in a nontangible, usually
mathematical or visual, manner. Interesting aspects of the product are
analyzed, rather than built.
•2) Comprehensive: they implement most, if not all, all the attributes of a product.
A comprehensive prototype corresponds closely to the everyday use of the word
prototype, in that it is a full-scale, fully operational version of the product
oFocused: they implement one, or a few, of the attributes of the product.
What are prototypes used for? 4 purpose!
•Learning: will it work?, how well does it meet the customer needs?
•Communication: prototypes enrich communication with top management.
Vendors, partners, extended team members, customers and investors.
•Integration: Prototypes are used to ensure that components and subsytems of the
product work together as expected. Comprehensive physical prototypes are most
effective as integration tools in product development projects because they require
the assembly and physical internconnection of all the parts and subassemblies that
make up a product.
•Milestones: Particularly in the later stages of product development, prototypes
are used to demonstrate that the product has achieved a desired level of
Principles of Prototyping
•Analytical prototypes are generally more flexible than physical prototypes
oBecause an analytical prototype is a mathematical approximation of the
product, it will generally contain parameters that can be varied in order to
represent a range of design alternatives. In most cases, changing a
paramenter in analytical prototype is easier than changing an attribute of a
•Physical Prototypes are required to detect unanticipated phenomena
oA physical prototype often exhibits unanticipated phenomena completely
unrelated to the original objective of the prototype.
•A prototype may reduce the risk of costly iteration
oa prototype may reduce the risk of costly iteration. Taking time to build
and test a prototype may allow the development team to detect a problem
that would otherwise not have been detected until after a costly
development activity, such as building an injection mold.
•A prototype may expedite other development steps
oSome the addition of a short prototyping phase may allow a subsequent
activity to be completed more quickly than if the prototype were not built.
•A prototype may restructure task dependencies
•3D CAD Modeling and analysis
oFree-form fabrication technologies enable realistic 3D prototypes to be
created earlier and less expensively than was possible before.
Planning for Prototypes
•Step 1: Define the purpose of the prototype
oIn defining the purpose, the team lists its specific learning and
communication needs. Team members also list any integration needs and
whether or not the prototype is intended to be one of the major milestones
of the overall product development project.
•Step 2: Establish the level of Approximation of the prototype
oPlanning a prototype requires definition of the degree to which the final
product is to be approximated.
•Step 3: outline an Experimental Plan
oIn most cases, the use of a prototype in product development can be
thought of as an experiment. Good experimental practice helps ensure the
extraction of maximum value from the prototyping effort.
•Step 4: Create a Schedule for Procurement, Construction, and Testing
Planning Milestone Prototypes
•Alpha Prototypes: are typically used to assess whether the product works as
intended. The parts in alpha prototypes are usually similar in material and
geometry to the parts that will be used in the production version of the product,
but they are usually made with prototype production processes
•Beta Prototypes: are typically used to assess reliability and to identify remaining
bugs in the product. These prototypes are often given to customers for testing in
the intended environment.
•Preproduction prototypes: are the first products by the entire production
process. At this point the production process is not yet operating at full capacity
but is making limited quanitities of the product.