SOFTWARE DESIGN FOR SIX SIGMA (DFSS) RISK MANAGEMENT PROCESS - Software Design for Six-Sigma: A Roadmap for Excellence - page 402

TABLE 15.2 Software Severity Rating

Severity of Hazard/Harm

Rating Rating

Criteria Description 1-5 1-10

Catastrophic Product Halts/Process Taken Down/Reboot

Required : The product is completely hung up,
all functionality has been lost and system
reboot is required.

5 9-10

Serious Functional Impairment/Loss : The problem will

not resolve itself and no “work around” can
bypass the problem. Functionality either has
been impaired or lost, but the product can still
be used to some extent.

4 7-8

Critical Functional Impairment/Loss : The problem will

not resolve itself, but a “work around”
temporarily can bypass the problem area until
it is fixed without losing operation.

3 5-6

Marginal Product Performance Reduction : Temporary

through time-out or system load-the problem
will “go away” after a period of time.

2 3-4

Negligible Cosmetic Error : No loss in product functionality.

Includes incorrect documentation.

1 1-2

TABLE 15.3 Software Likelihood of Occurrence Rating

Likelihood of Occurrence Rating

Rating Rating

Criteria Description 1-5 1-10

Frequent Hazard/harm likely to occur frequently :1per10

min (1/10) to 1 + per min (1/1)

5 9-10

Probable Hazard/harm will occur several times during the

life of the software : 1 per shift (1/480) to 1 per
hour (1/60)

4 7-8

Occasional Hazard/harm likely to occur sometime during

the life of the software : 1 per week (1/10k) to 1
per day (1/1440)

3 5-6

Remote Hazard/harm unlikely but possible to occur

during the life of the software :1per1
unit-year (1/525k) to 1 per 1 unit-month (1/43k)

2 3-4

Improbable Hazard/harm unlikely to occur during the life of

the software : 1 per 100 units- years (1/50m) to
1 per 10 unit-years (1/5m)

1 1-2