cellpadding=0 cellspacing=0 width=100%>
Yahoo! is not affiliated with the authors of this page or responsible for its content.
Statement of Work Statement of Work
Background

Users

Operation

Restrictions

Cost

Resources

Risks

Background
The cost of electricity is presently rising at a steady rate. All types of consumers of electricity,
from landlords to office managers to the simple home user, are seeking more and more
information about the power consumption of their appliances and electronics in an effort to reduce
power usage and save money. It can be difficult to obtain power consumption data for most
appliances and electronics, and consumers often aren t sure of the best ways in which to reduce
power consumption. For years, large-scale industry has spent millions of dollars on equipment
and services in an effort to reduce its power consumption, but there is little such practical and
affordable help available to home and small office consumers.
Users

Background
Needs
Conscientious Home
Users
-Little knowledge of technical
electrical terms
-Concerned about rising energy
costs
-Simple, user-friendly device
-Low cost
-Useful with a variety of devices
Technically Inclined
Users
-Basic understanding of
electronics
-Seeking more advanced
information about power
consumption
-Access to more advanced data
-Moderately-low cost
-Modern appearance
Landlords, Property
Managers
-Concerned about tenants
energy usage
-Little knowledge of technical
electrical terms
-Accurate way of determining and
billing energy costs
-Must be sure the device has
been on and is giving an accurate
reading
Office Managers
-Responsible for larger-scale
power usage
-Very concerned with electricity
costs
-Quick setup, and easy to use
-More concerned with accuracy
and effectiveness
Salespersons
-Wish to be able to demonstrate
low-power devices
-Useful with a variety of devices
-Quick setup, and easy to use
Operation
Priority
Requirement
MUST
Display instantaneous cost of operating the device
MUST
Display instantaneous power usage
MUST
Allow user to input local electricity price or use a default; but
MUST NOT
Require the electricity cost input in order to display power usage
SHOULD
Display current and voltage data
SHOULD
Allow user to reset the device
SHOULD
Be easy to navigate between menus
SHOULD NOT
Require more than minimal setup time
SHOULD NOT
Require attention during operation
MIGHT
Display total past cost of operating the device
MIGHT
Display total past energy usage
MIGHT
Display power factor

Restrictions
Priority
Factor
Requirement
MUST
Environment
Operate in typical home temperature and
humidity conditions
SHOULD
Power Dissipation
Dissipate less than 20W during continuous
operation
SHOULD NOT
Electrical
Interfere with the operation of any downstream
devices
SHOULD NOT
Installation
Require mounting hardware
SHOULD NOT
Power Source
Require batteries
SHOULD NOT
Cooling
Require active cooling
MIGHT
Portability
Be sufficiently small, light and robust enough to
be portable
MIGHT NOT
Size
Exceed 2.5kg in weight

Cost

Prototype
Hand-Assembled Mass Produced
Quantity
1
~10
~1000
Estimate
$1000*
$150
$75
*Including the cost of any flash/programming equipment required for the microcontroller. Resources

Requirements
Source
Skills
Power & Power
Infrastructure
Knowledge
-Understand the principles and
technology behind power and its
distribution in North America
Team Members; Mentor
Analog & Digital Circuit
Design
-Select and implement appropriate
components in design
Team Members; Mentor
PCB Layout
-Correctly layout a printed circuit board
Team Members; Mentor
Low-level
Microcontroller
Programming
-Program the microcontroller to implement
the desired functionality in a robust
manner
Team Members; Mentor
Mechanical Assembly
& Packaging
-Devise a suitable package for the device
and assemble components into package
Team Members; Mentor
Electrical Assembly
-Solder components onto PCB
Team Members

Equipment
Design Testing
-Multi-meter, wattmeter, oscilloscope,
spectrum analyzer, power supply(s),
various electrical appliances
University Labs; Team
Members
Electrical Assembly
-Soldering equipment, wires & various
other small electrical equipment
University Labs; Purchased
Mechanical Assembly
-Miscellaneous tools, drill, glue, screws
University Labs; Purchased
Flash Programming
-Flash programmer for the microcontroller
University Labs; Purchased
Software Design
-Microcontroller programming software
Purchased
PCB Design
-PCB design software
University Labs;
Purchased/Sponsored

Services
PCB Fabrication
-Outsource to commercial supplier
Commercial Supplier

Other
Packaging
-Generic plastic package to be modified
as required
Team Members; Purchased
Risks
Level
Description
Response
High
Team does not have sufficient
analog and digital circuit design
experience.
Begin design process early in order to give team
time to work through design issues.
High
Effective means of measuring
current and voltage cannot be
devised.
Research available chips. If a suitable chip to
measure voltage cannot be found, a Hall effect-
type device can be used to measure current and
120V AC can be assumed.
Medium
Suitable microcontroller with
desired functionality cannot be
located.
Research available chips. If a suitable
microcontroller cannot be found, desired
functionality may have to be re-evaluated.
Low
PCB fabrication lead time could
add unacceptable delay to the
design process.
Begin design and fabrication as soon as
possible; Research lead times of various
suppliers.