Effect
Cause
Foot failing in down position
User would trip and fall
Sensor unable to detect
terrain or send faulty
readings
1
Actuator malfunction
2
Structural failure,
orthotic unable to
support equipment
Spring
Yielding/Buckling
Power supply
3
4
Importance
Risk Item
Severity
ID
Likelihood
MSD Project Risk Assessment: P13002
2
3
6
1
2
2
1
3
3
1
2
2
1
2
6
2
2
4
1
2
2
2
2
4
2
3
6
2
2
4
1
3
3
5
Scheduled deadlines not
met
Timeline falls behind,
other deadlines change
Material acquisition delay
Prototype cannot be
built and tested
6
Personal conflicts: time
management,
overloads schedule,
illness
Long lead times, parts
not ordered on time
7
Incorrect material handling
Overload system
capabilities
Misuse of supplies
Project failure,
unhappy customer
Weight of device too
heavy
8
9
Unable to meet customer
specifications
10
11
Device contains sharp
edges, harms the users
Action to Minimize Risk
Software fail safe, if no data is sensed
will fail in natural position
Owner
Engineering
Lead
System free to move if actuator
breaks
Large enough factor of safety
Engineering
Lead
Structural modification, mechanical
prevented action
Before system runs out of power,
lock in normal state. Warning signal
included
Communication among members to
know each other’s schedules,
understand critical path, seek help
when needed
Contact with vendors, determine
parts with long lead times, order by
week 7
Responsible team members in charge
of their components. Understand
system capabilities and specifications
Be cautious of component weights
when creating detailed design
Avoid using heavy metals, use
composites and plastics when
possible
Ensure all points of contact will not
harm user, no pressure points
Engineering
Lead
Engineering
Lead
Electrical
Engineers
Team
Manager
Team
Manager
Engineering
Lead
Engineering
Lead
ME- Pattie
Mechanical
Engineers
Memory overflow
Device would go into
an error state
12
Friction between sliding
components
Back mechanism
breaking
Small objects get stuck in
locking system
Jamming or blocking
the system from
moving
Mechanism firing at
incorrect time
13
14
Incorrect power to solenoid
15
Not enough memory
on the micro controller
and associated memory
systems
Friction effects on
system larger than
tolerances assumed
User kicks up small
objects; finger placed
between components
Mechanism
misinterprets terrain
Attachment to orthotic
16
Unable to read terrains
Device will not move in
proper position
17
Wiring come unconnected
Electrical components
become unattached
18
19
Sensors reading
surfaces such as grass,
snow,glass
Someone or something
pulling wiring out of
place
Unaxial bending force
applied
Fluid leaking out of valve
20
Fluid leaking out of piston
21
Fluid leaking out of storage
tank or connection tubing
2
2
4
2
3
6
1
2
2
1
3
3
1
3
3
1
3
3
2
2
4
1
2
2
1
2
2
1
2
2
1
2
2
1
3
3
1
3
3
1
2
2
22
Cylinder over pressurizing
Hydraulic system
would burst
Too much pressure
applied to cylinder
Hydraulic system
would burst
Hydraulic fluid freezing
in system
too much heat applied
to system
System too cold for
operating range
23
Fluid combustion
24
Fluid freezing
25
Ensure enough memory is available
on micro controller
Large factor of safety implemented
when determining the friction force
applied to the system
Design system to avoid large gaps
between orthotic and system
components
Fail safe design with isolated power
supply
Computer
Engineers
Mechanical
Engineers
Mechanical
Engineers
EE- Rob
ME- Pattie
Test the sensors on the surfaces to
determine all common surfaces that
a user will interact
Ensure that the wiring is protected
from foreign objects when system is
wired together
EE- Dana
Electrical
Engineers
ME- Shane
Take in account the sealing methods
Take in account the sealing methods
Take in account the sealing methods
between the main piston and the
storage tank and ensure the tubing is
properly fitted
Understand the operating pressure
and determine the full operating
range of cylinder
All parameters will function in the
safe range of -20⁰-120⁰F
All parameters will function in the
safe range of -30⁰-150⁰F
Mechanical
Engineers
Mechanical
Engineers
Mechanical
Engineers
Mechanical
Engineers
Mechanical
Engineers
Mechanical
Engineers
26
27
28
Likelihood scale
1 - This cause is unlikely to happen
2 - This cause could conceivably happen
3 - This cause is very likely to happen
Severity scale
1 - The impact on the project is very minor. We will still meet deliverables on time and within budget, but it
will cause extra work
2 - The impact on the project is noticeable. We will deliver reduced functionality, go over budget, or fail to
meet some of our Engineering Specifications.
3 - The impact on the project is severe. We will not be able to deliver, or what we deliver will not meet the
customer's needs.
“Importance Score” (Likelihood x Severity) – use this to guide your preference for a risk management strategy
Prevent Action will be taken to prevent the cause(s) from occurring in the first place.
Reduce Action will be taken to reduce the likelihood of the cause and/or the severity of the effect on the project, should the cause occur
Transfer Action will be taken to transfer the risk to something else. Insurance is an example of this. You purchase an insurance policy that
contractually binds an insurance company to pay for your loss in the event of accident. This transfers the financial consequences of the
accident to someone else. Your car is still a wreck, of course.
Accept
Low importance risks may not justify any action at all. If they happen, you simply accept the consequences.