BME Senior Design
Introduction to Design, Project Statement, and
Specifications
Introduction to Design
Engineering design involves the following three phases:
1. The first phase begins with an analysis of customer needs and ends with a general description of the product or device.
2. The second phase involves taking a product description and producing a prototype. This step involves performing feasibility studies, developing system architecture, identifying, designing, implementing, and testing the subsystems. Also included in this phase is integrating the subsystems, and building and testing the final prototype.
3. The third phase begins with the prototype and ends with a finished product in the marketplace. While this phase may be the most important in industry, it is equipment intensive and involves a significant scheduling and
management component. In the educational setting, this phase is not given the same emphasis as the second phase; however, students should be aware that all of these phases occur in industry.
Project Statement
A project statement or problem definition usually begins with a need expressed by a customer. The purpose of a project statement is to make absolutely clear the problem to be solved so that work can begin on the project, and once completed, the customer will be satisfied with the result. To ensure that a project statement can achieve its objective, communication with the customer is essential early in the design process.
Meet with the customer and discuss their expectations and project requirements.
It is essential that the student visits the customer’s site and collects information. Seeing the problem at the site will clarify any project uncertainties, and any physical restrictions will be observable and measurable.
Take good notes in your laboratory notebook!
A well-written project statement includes as much information as possible relating to the project, and usually includes five general categories of
projectthis requires a great deal of effort in order to do a good job. A project statement is a necessary and important step in the design process for without it, the project will never be successful and both the student and the customer will be unhappy.
Statement of Need
The first sentence describes a general global statement of need. Following this, enough information in described so that the client’s problem is clearly presented and does not present a solution to the problem. This section should be
approximately 1-2 paragraphs in length.
Introduction and Overview
Describe the project as completely as possible. The purpose of the device must be clearly stated. Give reasons for performing the design. What will the finished device do? What is unusual about the device? What claims are you making? All of these items should be contained in a narrative presentation. Numbers and figures may be included, but must also be given again in the specifications.
Realistic Constraints
Describe how the following constraints affect your project: economic;
environmental; sustainability; manufacturability; ethical; health; safety; social; and political.
Other Information
Everything that does not fit in the previous sections, but relates to the project, should be listed under this section. This could include information about client, client location, etc.
Questions
In investigating and describing a project, questions are raised that cannot be answered until later in the design process. These questions should be
documented. Questions include situations such as performance specifications, unknown restrictions, or related products.
It should be noted that the Project Statement is a document in progress and will change as work on the project continues. This document should be kept up to date and revised as new information is received.
Other Activities that are not required in your report, but are
informative and will be needed for your project proposal.
There are many activities that are carried out in preparing a Project Statement in industry. No single source is always the best. Since the activities carried out in Senior Design are different than those carried out by an engineer in industry, it is useful to at least briefly mention a few issues of inquiry usually carried out in industry, but not required here in Senior Design.
It is usually important to conduct a market survey to establish customer desires, pricing strategies and sales forecasts. This can be carried out using personal interviews, telephone interviews or mailed questionnaires. It is also important to investigate other sources of information such as ABLEDATA, the Census of
Manufactures published by the US Dept. of Commerce, Statistical Abstract of the
United States published by the US Bureau of Census, and other resources.
Investigating patent records will also determine the extent of workable ideas and protected ideas. The US Patent Office publishes the weekly Official Gazette that lists the latest patents. A library search may merit investigating to determine whether the project has been tried before and whether it was successful. This activity may also uncover any legal issues that should be determined before expenditure of manpower on the project.
There are a number of trade and technical journals that should be investigated. Attending trade shows is also important to find out what is going on in the industry.
SPECIFICATIONS
One of the most important parts of the design process is determining the requirements your senior design project must fulfill. These requirements are called specifications. There are many different types of specifications, including specifications for hardware and software. Only those that are relevant to senior design are discussed.
What Specifications Are and Are Not
Before the design of your project, you must determine how your project is required to function. To do this, operational specifications or requirements for your project are developed. These specifications determine the problem you are solving. The operational specifications must completely describe and define the design project.
The general idea of the specifications is that any competent engineer be able to design a device that performs the function that is desired. If several engineers designed the same device from the specifications, all of the designs would perform within the given tolerances and fulfill the specified requirements, but with different designs (and different components). Thus, your specifications determine what is to be built, and do not provide any information as to how to build the device.
This is analogous to changing the oil in your car. Your car’s owner’s manual specifies how often you must change the oil, but does not tell you how.
Likewise, you will state what must be designed, but not how to design the project in your specifications.
Moreover, you should not state or specify any components, such as the use of TTL components or a type of microprocessor. The use of the acronym “LED” is not be acceptable in your specifications because this implies a design choice has been made (better to state display and define character size, etc.). Further, no manufacturer’s name or components are listed. However, if you are modifying an existing device hardware or software you must state what the device is in as must detail as possible. In this case, you are free to describe the device by discussing its specific components such as a microprocessor, LED, TTL chip, etc. This is acceptable because it describes what exists and defines what changes must be made, but you must not discuss how the modifications are
implemented.
Technical Specifications
This section contains, in tabular form, all of the facts and figures needed to complete the design project. An acceptable example format is given below:
Material Specifications
Physical: Type of material (316 Stainless Steel, 6061 Aluminum, etc.
Mechanical:
Size: 4.2 x 3.7 x 1.8 inches (L x W x H)
Weight: 1.2 pounds (lbs)
Speed: 200 Revolutions per minute (RPM)
Power: ¼ Horsepower (HP)
Electrical:
Maximum Input Voltage: 16 Volts DC (VDC) Maximum Input Current: 2 Amps (A)
Maximum Output Voltage: 5 Volts (V) Maximum Output Current: 1 Amp (A)
Sampling Rate: 1 kHz
Battery Life: 40 hours Wireless: Frequency: 1.0-3.7 GHz Range: 10 – 30 meters Protocol: Bluetooth Environmental: Storage Temperature: -20 – 150 ºF
Operating Temperature: 68 – 90 ºF
Operating Environment: (indoors, outdoors, dust, humidity/moisture)
Software:
User Interfaces: (keyboard, voice, mouse, etc.)
Hardware Interfaces: (monitors, data acquisition equipment, robotics, etc.)
Communication Protocols: (RS-232, Bluetooth, Wi-Fi, USB, Ethernet, etc.)
Features: List any features the software will have.
Computer Requirements:
Operating System: Microsoft Windows 2000 – Windows XP SP3
Processor: 2GHz Pentium 4
Memory: 1 GHz
Safety:
List safety issues for the device relating to proper or improper use. List dangers to the user after prolonged use.
Maintenance:
List any potential routine maintenance required for the design.
NOTE: The above is only an example. You may not need all of the items shown in this example. You may need items not shown. Regardless, to truly identify what must be designed; your specifications must be as complete as possible.
Format for Project Statement & Specifications
Page One:Project Statement & Specifications Title of Project
TEAM # Team Members
Project for Client # or Industry Sponsor
Client Contact: Name(s), Organization, Address, and Phone Number.
Page Two and beyond:
Statement of Need (1-2 paragraphs)
The following should be no less than 4 pages in length
Introduction & Overview Realistic Constraints Other Information Questions
