Document Title: SCUBA2 Polarimeter Risk Assessment ... - JACH

SCUBA-2 Polarimeter Project Office
Université de Montréal
Département de physique
B. P. 6128, Succ. Centre-ville
Montréal, Québec
Canada H3C 3J7
Tel: 1-514-343-5816
Fax: 1-514-343-2071
Email: bastien@astro.umontreal.ca
WWW: http://www.astro.umontreal.ca/to_come...
Document Title:
SCUBA2 Polarimeter
Risk Assessment
Document Number: SC2/POL/PM500/002
Issue: Version 1.1
Date: 17 th November 2004
Document
Prepared By:
Document
Approved By:
Document
Released By:
Janos Molnar
PLM Project Manager
Pierre Bastien
Project Scientist
Janos Molnar
SCUBA2 Canadian
Project Manager
Signature and Date: 17 th Nov. 2004
Signature and Date: 17 th Nov. 2004
Signature and Date: 17 th Nov. 2004
The information contained in this document is strictly confidential and is intended for the addressee only.
The unauthorised use, disclosure, copying, alteration or distribution of this document is strictly prohibited and may be unlawful.
SCUBA-2 POL Risk Assessment, version 1.1 Page 1 of 11

Change Record
Issue Date Section(s) Affected Description of Change/Change
Request Reference/Remarks
0.1 09/10/03 Initial document
0.2 14/10/03 Risks 2, 3 and 5 Additional information added in
preparation for the CoDR
1.1 17/11/04 All changes, additions are shown
in italics
Renamed document, updated for
the PDR
SCUBA-2 POL Risk Assessment, version 1.1 Page 2 of 11

Introduction
The Polarimeter for SCUBA-2 (POL-2) is a medium-risk, high-reward project.
The POL-2 development project has a limited and fixed budget and a much reduced
development cycle due to the late approval of POL-2 by the JCMT Board of Directors as
an essential auxiliary instrument for SCUBA-2. The additional risk, posed by this fact is
still considered manageable by the POL-2 Team.
The Process
After the initial review of the instrument requirements projects typically start with a high
level of risk that is then reduced by the implementation of mitigation steps within the
project plan, changing the requirements or developing a better understanding of the
engineering/programmatic challenges.
To help manage risk the project management team has adopted the standard UK ATC
risk management strategy which:
a) identifies the key risks in the project
b) assigns a hazard (severity) level to each risk on a scale of 1 to 5 (5 is very high
severity and would be terminal to the project if it occurred - infinite schedule
delay).
c) assigns a probability of occurrence of the risk (0 to 4) (5 is > 50% probability), 1
d) multiplies the two numbers to come up with the risk level (Impact)
e) tracks, with regular updates, all risks with a level of 6 or higher (9 is regarded as
high risk)
f) assigns cost and schedule impact to all tracked risks
g) puts in place risk mitigation steps designed to bring the risk down to the
acceptable level, estimates the risk level after the implemented steps and forecasts
the date when the risk will reach the acceptable level and is eliminated
Although Université de Montréal has accumulated significant experience in building
polarimeters, it is possible that with the selected mode of operation some difficult
technical problem might yet be uncovered that would put the delivery date too far back or
require large amounts of new funds to overcome. The risks applicable to the Polarimeter
will be tracked separately and are described in the following tables.
1 If probability of occurrence is higher, than 0.5, the risk will be treated as certainty and be part of the development plan
SCUBA-2 POL Risk Assessment, version 1.1 Page 3 of 11

Risk Number POL/1 Status Live
Date Logged October 2003 Date Cleared
On Critical Path Yes WBS Ref. No. x.x
Owner
Mike Fich, Gary Davis
Original Risk Factor Prob: 5 Severity: 5 Impact (P*I) = 25 Cat = High
Mitigated Risk Factor Prob: 1 Severity: 5 Impact = 5 Cat = Medium
Updated Mitigated Risk Factor Prob: .5 Severity: 5 Impact = 2.5 Cat = Low
as of Nov.19th
Date when risk is forecast to
be passed:
Apr.2004 -> Apr.2005
Description of risk:
Additional Canadian funding will not be available to complete SCUBA-2 development in its original
configuration, so available funds allocated to Polarimeter development will be redirected
Impact on project cost, schedule or quality if risk realised without mitigation:
Polarimeter won’t be developed for SCUBA-2
A potential for achieving the best polarimetry in sub-millimetre range won’t be realized for the JCMT user
community
Schedule Delay: none
Cost:
none
Mitigation action:
1. Secure additional funding through OIT
2. Secure additional funding through inviting new partners and or private donations
Hence the re-assessment is that the Probability and Impact have been reduced by 80%.
November 19 th 2004 update:
a. The JCMT Board of directors deemed the polarimeter an essential auxiliary instrumentfor SCUBA-2,
which means that its development won’t be halted to redirect funding to support other SCUBA-2
specific work.
b. Negotiations are ongoing to extend the lifecycle of JCMT, which would open up opportunities for
additional funding by new potential SCUBA-2 users
Hence the probability of discontinued funding for the polarimeter development alone is further reduced.
Impact on project cost, schedule or quality if risk realised with mitigation action:
Polarimeter won’t be developed for SCUBA-2
A potential for achieving the best polarimetry in sub-millimetre range won’t be realized for the JCMT user
community
Schedule Delay:
Cost:
none
none
SCUBA-2 POL Risk Assessment, version 1.1 Page 4 of 11

Risk Number POL/2 Status Live
Date Logged October 2003 Date Cleared
On Critical Path Yes WBS Ref. No. x.x
Owner
PB, JM
Original Risk Factor Prob: 3 Severity: 3 Impact (P*I) = 9 Cat = High
Mitigated Risk Factor Prob: 1 Severity: 3 Impact = 3 Cat = Medium
Updated Mitigated Risk Factor Prob: .5 Severity: 3 Impact = 1.5 Cat = Low
as of Nov.19th
Date when risk is forecast to
be passed:
September 2005 -> April 2005
Description of risk:
Manufacture of the sapphire wave-plate by QMC Instruments Co., Cardiff gets significantly delayed
Impact on project cost, schedule or quality if risk realised without mitigation:
Potential for delays in testing of the wave-plate and eventually delivery of the polarimeter.
Schedule Delay: tbd
Cost:
$US 10,000/month
Mitigation action:
1. Keep in close contact with supplier and adjust internal deliveries to minimise impact
2. Explore alternative supplier
3. Use a monochromatic halfwave plate centered in the middle of the 850 µm bandpass. This
would allow a less efficient use of the instrument in one band only. A manufacturer for
that monochromatic wave plate would still be required.
Hence the re-assessment is that the Probability has been reduced by 67%.
November 19 th 2004 update:
QMC signed off on the project plan, which shows the delivery of wave-plate in April 2005
Hence the risk of late wave-plate delivery is further reduced
Impact on project cost, schedule or quality if risk realised with mitigation action:
Schedule Delay:

Risk Number POL/3 Status Live
Date Logged October 2003 Date Cleared
On Critical Path Yes WBS Ref. No. x.x
Owner
PB
Original Risk Factor Prob: 5 Severity: 1 Impact = 5 Cat = Medium
Mitigated Risk Factor Prob: 2 Severity: 1 Impact = 2 Cat = Low
Updated Mitigated Risk Factor Prob: 4 Severity: 1 Impact = 4 Cat = Medium
as of Nov.19th
Date when risk is forecast to
be passed:
April 2004 -> May 2005
Description of risk:
Full potential of SCUBA2 polarimetry is not utilised due to excessive loss through the sapphire wave-plate at
ambient temperature at 450 µm
Impact on project cost, schedule or quality if risk realised without mitigation:
Lost sensitivity
Schedule Delay: none
Cost:
none
Mitigation action:
1. Build polarimeter’s own cryostat
Hence the re-assessment is that the probability has been reduced by 60%
November 19 th 2004 update:
Preliminary research by UWC indicated that putting the wave-plate into its own cryostat is not helping so
the probability of this happening has increased, but its severity has been reduced
There is additional research going on at UWC, which if successful, might eliminate the loss problem
altogether
Hence the risk of excessive loss at 450µm has gone up.
Impact on project cost, schedule or quality if risk realised with mitigation action:
Schedule Delay:
Cost:
none
$US 75,000 -> none
SCUBA-2 POL Risk Assessment, version 1.1 Page 6 of 11

Risk Number POL/4 Status Live
Date Logged October 2003 Date Cleared November 04
On Critical Path Yes WBS Ref. No. x.x
Owner
PB
Original Risk Factor Prob: 3 Severity: 2 Impact = 6 Cat = High
Mitigated Risk Factor Prob: 1 Severity: 2 Impact = 4 Cat = Low
Updated Mitigated Risk Factor Prob: 0 Severity: 1 Impact = 0 Cat = 0
as of Nov.19th
Date when risk is forecast to
be passed:
April 2004
Description of risk:
Not getting all the technical information about the mechanical mounting of the polarization module –
information coordinated by ATC
Impact on project cost, schedule or quality if risk realised without mitigation:
Late information will lead to delays in the project
Incomplete information may result in redesign
Schedule Delay: 3 months
Cost: $US 30,000
Mitigation action:
1. Establish close working relationship with ATC and UWC Mechanical Design group
2. Get Polarimeter Design Reviewed and accepted by ATC and UWC Mechanical Design
group
3. Establish process by which any mechanical design change to the optics and cryostat has to
be acknowledged by the Polarimeter design prime
Hence the re-assessment is that the probability has been reduced by 67%
November 19 th 2004 update:
We have gotten sufficient information on the available to us space for the polarimeter. We are not quite
pleased with the allocated space envelop, which by itself introduces new risks, but at least has eliminated
this one.
Hence the risk of late design information has been eliminated.
Impact on project cost, schedule or quality if risk realised with mitigation action:
Schedule Delay: 1.0 months -> 0
Cost: $US 10,000 -> 0
SCUBA-2 POL Risk Assessment, version 1.1 Page 7 of 11

Risk Number POL/5 Status Live
Date Logged October 2003 Date Cleared
On Critical Path Yes WBS Ref. No. x.x
Owner
PB
Original Risk Factor Prob: 3 Severity: 3 Impact = 9 Cat = High
Mitigated Risk Factor Prob: 3 Severity: 1 Impact = 3 Cat = low
Updated Mitigated Risk Factor Prob: 2 Severity: 1 Impact = 2 Cat = low
as of Nov.19th
Date when risk is forecast to
be passed:
May 2005
Description of risk:
Getting all the technical information for running the polarization module in step with the rest of SCUBA-2 on
time
Impact on project cost, schedule or quality if risk realised without mitigation:
Delay in the project
Schedule Delay: tbd
Cost:
$US10,000/month
Mitigation actions:
By ensuring that the position of the wave plate (from the encoder) is recorded in the header of each individual
image will guarantee that the polarization module will run in step with the rest of SCUBA-2
Hence the re-assessment is that the probability remains significant, but the severity has been reduced to a
minimal level
November 19 th 2004 update:
We have gotten sufficient information on the available to us space for the polarimeter. We are not quite
pleased with the allocated space envelo, which by itself introduces new risks, but at least has eliminated
this one.
Hence the risk of late design information has been eliminated.
Impact on project cost, schedule or quality if risk realised with mitigation action:
Schedule Delay: none
Cost: $0
SCUBA-2 POL Risk Assessment, version 1.1 Page 8 of 11

Risk Number POL/6 Status Live
Date Logged June 2003 Date Cleared
On Critical Path Yes WBS Ref. No. n/a
Owners
PB
Original Risk Factor Prob: 2 Severity: 3 Impact = 6 Cat = High
Mitigated Risk Factor Prob: 1 Severity: 2 Impact = 2 Cat = Low
Date when risk is forecast to
be passed:
December 2005
Description of risk:
Critical support staff leaves the project
Impact on project cost, schedule or quality if risk realised without mitigation:
Design complexity requires significant learning curve for new staff to get up to speed.
Worst case scenario would be if critical staff left at the start of module test and system integration
Schedule Delay: 3 months
Cost: $US 30,000
Mitigation action:
1. Create stable and rewarding work environment.
2. Minimise work overload and eliminate burn-out.
3. Demand detailed and clear design documentation at every stage of the design
4. Store all design information in clearly structured and easy to use secure database
Impact on project cost, schedule or quality if risk realised with mitigation action:
Schedule Delay: 1 month
Cost: $US 10,000
SCUBA-2 POL Risk Assessment, version 1.1 Page 9 of 11

Risk Number POL/7 Status Live
Date Logged November 2004 Date Cleared
On Critical Path Yes WBS Ref. No. n/a
Owners
PB
Original Risk Factor Prob: 4 Severity: 2 Impact = 8 Cat = High
Mitigated Risk Factor Prob: 1 Severity: 2 Impact = 2 Cat = Low
Date when risk is forecast to be
passed:
May 2005
Description of risk:
Unexpected change in wave-plate position (relative to cryostat window) requires more complex mechanical
design if we want to maintain the maximum possible efficiency for polarimetry.
Impact on project cost, schedule or quality if risk realised without mitigation:
Full potential and efficiency of SCUBA-2 Polarimeter won’t be achieved
Schedule Delay: 0
Cost: 0
Mitigation action:
1. Develop more elaborate mechanical mounting of the waveplate.
2. Hire experienced mechanical design contractor to develop reliable and safe mounting mechanism.
3. Search for larger sized wave-plate
4. Search for alternative wave-plate implementation
Impact on project cost, schedule or quality if risk realised with mitigation action:
Schedule Delay: 1 month
Cost: $US 10,000
SCUBA-2 POL Risk Assessment, version 1.1 Page 10 of 11

Risk Number POL/8 Status Live
Date Logged November 2004 Date Cleared
On Critical Path Yes WBS Ref. No. n/a
Owners
PB
Original Risk Factor Prob: 4 Severity: 2 Impact = 8 Cat = High
Mitigated Risk Factor Prob: 2 Severity: 2 Impact = 4 Cat = Medium
Date when risk is forecast to be
passed:
May 2005
Description of risk:
Attainable observing modes (due to mechanical, control or computational limitations) don’t allow maximum
possible efficiency for polarimetry.
Impact on project cost, schedule or quality if risk realised without mitigation:
Full potential and efficiency of SCUBA-2 Polarimeter won’t be achieved
Schedule Delay: 0
Cost: 0
Mitigation action:
1. Develop option of POL-2 providing RTS signal for the SCUBA-2 and telescope control complex.
2. Enhance existing or develop new data processing algorithms for polarimetry.
3. Accept unavoidable limitations
Impact on project cost, schedule or quality if risk realised with mitigation action:
SCUBA-2 Polarimeter performance and efficiency will be closer to their full potential at the price of
Schedule Delay: 2 month
Cost: $US 20,000
SCUBA-2 POL Risk Assessment, version 1.1 Page 11 of 11