On this page I'm explaining what I mean by certain terms, particularly in relation to the project activities and deliverables I refer to in discussions, proposals and quotes - I hope this will serve to align our expectations.

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Application software

I consider application software to be all software that runs on devices that are external to the hardware product we are designing - on a PC, PDA, tablet or smart phone. Application software is sometimes part of the scope of our projects, but for software-only project I'll be happy to refer you to one of my associates.
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Bill-of-Materials (BoM)

A Bill-of-Materials is a list that specifies all parts and sub-assemblies that go into making a product, and this is part of the Engineering Documentation Pack we produce at the end of the detailed engineering phase. A final BoM can only be produced when engineering has been completed, but creating a draft BoM is very useful exercise in the early phases of a development project as it allows us to make a production cost estimate - although it must be noted that the BoM only lists the parts, not the assembly activities and costs.
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Breadboard

This to me is a distributed physical model build to run a series of experiments on design parameters for the intended product. It is primarily a test bench where elements of the design can easily be adjusted or exchanged, not a representation of the intended product. A breadboard is often of modular construction, and some effort is spent on making adjustments and measurements easy and repeatable.

Breadboards model only those product elements for which operating parameters need to be determined early on in the design process - especially where these parameters are inter-related. An example is an airflow model where the effect of a number of choices for fans, filters and channel geometry impact the design choices. The example shown above is a Microbench setup for a medical imaging device where lenses, illumination and camera modules can be quickly exchanged and adjusted.
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CAD model

I create 3D CAD (Computer Aided Design) models using Alibre Design Expert software. Like most other popular CAD packages, Alibre is a solid modeller; it creates 3D volumes by adding or removing material from a 3D shape - clicking here takes you to a page with a number of demo videos on the Alibre website.

The CAD model is my master document that describes the geometry of custom parts, and the relationships between parts in an assembly. From the model I can create:

• STEP and STL files as direct input to rapid prototyping suppliers or the CAM-software for my CNC-mill
• 3D PDF files to communicate designs to others who don't use CAD software
• Engineering drawings
• Photorealistic renderings
• Finite Element models for numerical engineering analysis
• Files that allow interchange of geometry data between all common CAD packages (STEP, IGES, ACIS, Parasolid and Solidworks). However it must be noted that although the part geometry will be accurate, the history of how the part was created is usually lost - the part becomes a "dumb solid"

My reason for choosing Alibre Design instead of more mainstream programs such as Solidworks, Inventor or Pro/Engineer is that Alibre offers very similar functionality for a fraction of the cost. I can thoroughly recommend Alibre for those without large libraries of legacy files.

When I specify a CAD-model or CAD-files as part of my deliverables for a project, unless otherwise agreed this means native Alibre Design files and 3D PDFs. If other file formats are needed I can either export to an interchange format, or have one of my associate CAD technicians rebuild the geometry in another CAD program.
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CAD Sketch

I use the term CAD Sketch for CAD models that are not worked out in detail, but just enough to communicate concept designs. CAD sketches don't take account of how parts are produced or assembled - that can be sorted out later. A CAD sketch is a good basis for a rendering.
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CE-marking

CE-marking is the application of the symbol on the left to the labeling of a product - it is the manufacturers declaration that the product complies with the essential requirements stated in one of many European Community Product Directives, covering health, safety and environmental protection legislation. A product that does not comply cannot be legally marketed in the EC.

In principle this is a manufacturers self-declaration, although in some cases (e.g. certain classes of medical devices) there is a requirement that the test that show conformity are performed by an accredited test house. In practice most of the work related to proving a device meets the requirements are in the tests for Electromagnetic Compatibility (EMC). For some projects we've done these tests ourselves hiring test facilities close by, for others we've worked with UKAS accredited test houses.

The most important product directives that we encounter are the Medical Devices Directive, the In Vitro Diagnostics Medical Devices Directive, the Measuring Instruments Directive and the more general Low Voltage Directive
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Circuit Schematic

A circuit schematic or circuit diagram shows the functional electronic elements of a design, and their electrical connections. Most electronic designs first start with a sketched block diagram, after which each of the blocks is worked out into a schematic on component level. We use either EAGLE or PROTEL to do this, and publish the schematics as PDF files.
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Engineering Drawing

I do all of my mechanical design in a 3D CAD package, and the models this produces precisely and unambiguously represent my design intent. However there are still many uses for classical 2D engineering drawings. One use is to indicate dimensional and geometrical tolerances, as this information is not present in the CAD model. I create Engineering Drawings in accordance with BS 8888 (which references the international ISO standards) using Alibre Design, and deliver them as PDF's.
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Engineering Documentation Pack (EDP)

This is the collection of all documents that specify a product design at the end of the detailed engineering phase - this is what a (contract) manufacturer would need to set up series production. The DDP includes CAD models, engineering drawings, circuit schematics and PCB layout, lens prescriptions, wiring diagrams, parts list, and documented firmware source code and executables. The EDP is used to make parts for the Reference Prototype.
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Engineering Prototype

The difference between an Engineering Prototype, lab models and product demonstrators is that in the former all parts and modules are made to not only be functionally representative, but are made according to production intent - taking into account constraints imposed by the intended production process. If a part is to be injection moulded, it will have draft, even wall thickness and take into account the mould geometry (e.g. side actions).
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Firmware

Firmware is software running on processors embedded in the products we design - as opposed to application software which runs on a PC, PDA or smart phone to which the products we design might be connected. When we deliver Firmware this consists of both annotated source code (usually written in C - this is the readable "program listing"), and the binary files that have to be loaded onto the embedded processors. In most cases loading firmware from a PC onto an embedded processor will require the use of a small piece of hardware - the programmer - and the installation of programming software on the PC.

We frequently use Atmel AVR embedded processors, for which we supply our clients with the software and hardware they need to update firmware on the models and prototypes we deliver. We also use the mbed ARM Cortex-M3 board which can be programmed over USB by drag-and-drop without additional hardware.
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Finite Element Analysis

Gerber files

Gerber files are the industry-standard format to specify printed circuit boards. "Gerbers" are actually collections of files each containing a 2D graphic depicting one aspect of the PCB - either a copper layer, silkscreen print, solder mask, or solder paste stencil. They only specify the geometry of the printed circuit board in terms of pads, tracks and areas; They contain no data on the circuit schematic or the component list.
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Handling Model

This is a non-functional model of representative dimensions and shape, intended to collect user feedback on ergonomics and styling. Concept-phase handling models are typically improvised from wood, clay and everyday objects - like the "medical imager" on the right. In later phases blue foam models or rapid prototyped parts are used. Under handling models I include user-interface mock-ups on PDAs or PCs - PowerPoint can be used to good effect here.
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Intellectual Property Rights (IPR)

Our project work regularly gives rise to patentable inventions, original designs or copyrighted material such as software programs. My default position is that if this occurs as part of a project fully funded by a client, all resulting IPR will be assigned to that client. In the case of inventions, it is our clients choice whether to pursue a patent, to publish or to keep secret. They will also have to bear all costs associated with protecting the IP. We do retain our moral rights to be identified as the inventor, designer or author.

An important point here is that although we will typically consult the Esp@cenet patent database, I can't guarantee that any designs or engineering solutions we come up with do not infringe on the IPR of others - it is up to our clients to make sure they have freedom to operate. The same applies to design rights.
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Lab Model

A Lab Model (LM) is an integrated functional model intended to test and demonstrate how sub-functions interact in the intended product. It is functionally but not necessarily geometrically representative of production intent - but it will typically be of a similar size and general layout. A lab model is intended to operate within a narrower set of parameter values then a breadboard and will therefore be much less adaptable. Functions with low technical risk will often still be implemented using off-the-shelf items, e.g. power supplies, microcontroller evaluation boards, RC-servos.
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Microbench

Microbench is a very flexible optical breadboarding system marketed by Linos Photonics. Other suppliers (e.g. OWIS) have compatible systems. We've used Microbench set-ups for a number of projects - most of the parts will be off-the-shelf but there will always be a few that I'll adapt or make from scratch. If you want to build smaller, there's also a Nanobench system!
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Napkin Sketch

This is a rough sketch - along the lines of a quick sketch on the back of a napkin. No artistic quality (at least not when I've sketched it), it only serves to illustrate concepts and facilitate discussions. Still extremely useful though - we make loads of these for most projects. If I state "napkin sketch" as deliverable, don't expect anything more presentable!
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PDF

The Portable Document Format was originally invented by Adobe but is now the de-facto open standard for documents that need to preserve their layout and formatting independent of the device on which they are viewed or printed.

What is not widely known is that Adobe Reader 8.1 and later can be used to view 3D PDF files, enabling the viewer to interactively manipulate a 3D model. Besides rotate, pan and zoom it is also possible to explore the parts tree and hide parts or whole sub-assemblies. Download this 3D PDF file to try it. Note that this will not work with some non-Adobe PDF readers. I use 3D PDFs extensively to communicate with clients, suppliers, and associates.

Presentation Model

This is a non-functional model that is representative in appearance - intended to convey the look and feel of the intended product. In that sense you can call it a "tangible rendering". We make presentation models by rapid prototyping or by machining from modeling boards, finished to a high cosmetic standard. They may include dummy functionality - the presentation model of a laboratory instrument shown here contained the innards of a digital photo frame - showing a number of possible user interface approaches. Presentation models are primarily used to pre-sell products that are still in development.
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Printed Circuit Board (PCB)

We use two kinds of PCBs in our projects. In most cases we'll have PCBs produced from our Gerber files by specialist suppliers - and these will include solder masks and silkscreen print. Most of our PCBs will be two-layer boards (top and bottom copper layer), but for some applications it might be necessary to use multi-layer boards - Very complicated boards like PC motherboards contain 20 layers or more. As only the top and bottom layers are visible to the eye and accessible with measuring probes we avoid multi-layer boards when the circuit is not yet finalised and proven.

Simple and small PCBs that we need fast I sometimes make in-house - see here for a description of the process and its limitations.
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Product Demonstrator

This is a model that looks like and works like a production version, but where the design was not detailed taking into account all the limitation of series production - in that sense they differ from Engineering Prototypes. This means that a product demonstrator can be made at a fraction of the cost of a true engineering prototype.

A product demonstrator is like a functional concept car. They are excellent in allowing potential users to gain first-hand experience at an early stage - this will allow the incorporation of their feedback in the production versions. They can show end-users or marketing partners that your technology can be succesfully implemented in a product.
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Proof-of-Concept

I make a distinction between Proof-of-Concept and Proof-of-Principle. To me the latter proves the physical principles behind a technology, while the former demonstrates the feasibility of a particular embodiment. Take for example the Inscentinel VASOR: The principle is: "Bees predictably extend their proboscis when exposed to a target odour they've been conditioned for". That was proven on a lab bench by observation. The design concept behind the VASOR is to detect the proboscis extension of an immobilised bee by measuring the obscuration of an IR beam.

The proof-of-concept model of a luminometer on the left was built in an hour or so to check if a simple photodiode was sensitive enough to detect chemiluminescence. It was.

Proof-of-Concept models are not intended for repeated use - they're made up of sticky tape, blu-tack, cannibalised parts and whatever else is at hand. In many cases there is some imagination required to see what the model actually proves.
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Proposal

A proposal expresses how I plan to implement a development project; it includes assumptions, activities and deliverables as well as estimates for project timeframe and cost. It is a sales document that basically says: "If you hire Panchromos, here's how we approach the work, here's what you'll get and here's how long I think it will take and what I think it will cost". Once the projects starts I'll do my best to stick to plan presented in the proposal. But in most cases once the work starts insights will change. Technically things might not work as well as we thought. On the other hand we might find shortcuts - e.g. an off-the-shelf component or module that saves us from designing something from scratch. Meeting regulations might require a change of concept. A part we plan to use may become obsolete. You get the idea.

One of the advantages we can offer is flexibility - we both need to be flexible in order to create the best value for the time and money spent.
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Quote

To me a quote is different from a proposal in that a quote gives a fixed price for a specific deliverable, whereas a proposal expresses intentions and cost estimates that may be revised once the project is underway. I can only give quotes for those projects where my ability to come up with the deliverables has limited exposure to external project risks - mainly technical risk (i.e. "it doesn't work as initially thought") .
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Rapid prototyping

When I refer to parts made by rapid prototyping I usually mean plastic parts as one-off or in very low numbers by additive layer manufacturing process such as Stereolithography (SLA), Selective Laser Sintering (SLS) or Fused Deposition Modelling (FDM). Depending on geometry parts can be build in a few hours, usually overnight. Parts made by these processes need quite labour-intensive filling and sanding to make them smooth enough to mimic moulded parts, usually doubling the part cost. In practice it is best to allow at least one week from sending off the 3D CAD files to having a smooth painted part ready for further assembly.

There are also additive processes that can make functional metal parts, but I have not used these yet.
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Reference Prototype

A Reference Prototype (RPT) is an Engineering Prototype (EPT) made at the end of the detailed engineering phase, using documentation prepared for the Engineering Documentation Pack. This means it's a fully functional model where all parts are made according to production intent - so taking into account the constraints of the chosen production processes although the model parts may still be made using prototyping technology. If any changes to the design are made after the RPT is built those changes should be physically implemented on the RPT, or where this is not practical a register of differences is kept.
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Rendering

An image that shows a digital 3D model in such a way that it looks like a photograph of the physical thing. I use Keyshot software to create renderings from CAD models and CAD sketches I create in Alibre Design - see the example below of a vacuum pick-and-place tool that I can mount on my CNC-mill. Renderings can be further retouched in the same way as photographs using image editing software such as Photoshop or Gimp.

Renderings are a great way to communicate design intent to non-technical persons - a photograph gives them a better feel for the product then a technical CAD-drawing. This makes renderings excellent for collecting stakeholder feedback on concept designs.
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RoHS

RoHS legislation restricts the use of certain hazardous substances (lead, mercury, cadmium, hexavalent chrome and some organic compounds) in electrical and electronic equipment. All electric or electronic equipment that is brought to market in the EU needs to meet the requirements of the RoHS directive, and we make sure this is the case when we deliver production-ready designs to clients. However unless specifically agreed otherwise all models & prototypes that we build and deliver in the course of a product development project will not be RoHS-compliant. The reason for this is that the lead-free solder that is required to make PCBs RoHS-compliant is more difficult to work with in non-production settings, which can lead to dry solder joints and intermittent contact problems.
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