Re: Shuttle Safety [was: Re...
- From: "columbiaaccidentinvestigation" <columbiaaccidentinvestigation@xxxxxxxxx>
- Date: 15 Jul 2006 10:56:14 -0700
Budget pressures on orbiter safety upgrades
This outside pressure for nasa to reduce demands placed on the national
budget resulted in an increased pressure to place a "greater emphasis
on cost efficient operations, while still maintaining safety with in
nasa space shuttle operations. The changing of priorities from a post
challenger environment of preventing another tragedy to Cost Saving
Measures implemented in the 1990's is factual and documented in the
kraft report of 1995 (*1). As the budgetary priorities of the
administrations office of management and budget (OMB) and congresses
congressional budget office (CBO) were focused on reducing the yearly
deficit by reduction on spending, increased taxes, and early retirement
of the national debt, all of which yielded the unified (social
security, Medicare trust funds included) budgetary surplus of 2000.
The historical tug of war between safety and costs in our space program
is easily seen in how for decades the aerospace safety advisory panels
(ASAP *2) recommendations for nasa to improve safety, and nasa
responding back to the asap by either accepting or rejecting those
recommendations (*3). The intrinsic problem created by the cbo and omb
budgetary pressures to bring program spending down was this then forced
nasa to request additional funding from congress in order to implement
the asap's recommendations, directly placing the cost of increasing
safety against the priority of cost reductions. But given the fact cbo
in the 90's was requesting budgetary restraints on nasa's part, the
bias shifted from a post challenger era of funding safety
recommendations, to the new priority of the 90's cost reductions and
shuttle safety suffered as documented by the caib (*4). The results of
outside pressures of budget reductions on orbiter safety was best
stated by the caib "Funding a safety upgrade in order to fly safely,
and then canceling it for budgetary reasons, makes the concept of
mission safety rather hollow." (*5)
How to calculate the benefits of safety upgrades a qualitative approach
In discussions about safety the equation referencing how many x dollars
is society willing to spend to produce y amount of reduced risk in
order to provide that a shuttle crew be safer does not fully represent
reality as the intrinsic and dollar value of a human life is not
represented in the equation. This is a common problem nasa faces when
justifying the additional program funding necessary to implement the
asap's safety recommendations, and that is how to quantify in a
dollar value the act of preventing the death of a crew and loss of a
vehicle. This is not easy for nasa as measuring the results from
dollars invested into increasing safety in our space program cannot be
compared to the private sectors investments and profit returns, for in
the private sector the point of diminishing returns for investments is
a function of profit, but nasa does not generate a profit and therefore
for accounting purposes safety investments are weighed against costs as
can be seen in the 1996 human space flight budget estimates (*6). But
current cost estimating for our space program is described as
estimating the future in dollars (*7), therefore when estimating the
returns from safety investments, the intrinsic or dollar values of
saving lives are not easily reflected as can be seen in the equation of
x dollars and y risk, lacks the a variable of human lives saved.
The variable s, the cost for making the orbiter safer for flight crews
Firstly the concept of risk analysis is measuring and analyzing what
can go wrong, how likely it is to occur, and what the consequences are,
and nasa's concept of safety is the freedom from conditions that
cause death or injury (*8). By nasa's own terms risk and safety are
the two definitions that are independent and therefore when
constructing an equation of how much funding is necessary to improve a
component, reducing the risk of system failure, and increasing crew
safety, the benefits of lives saved must be weighed in the equation for
it to represent reality. Let's say the variable "s" represents
the dollar value lost with the death of a crew, as this would bring
balance to the equation in representing the real benefits of a crit 1
failure being prevented by an upgraded component. Now to attempting to
correlate a dollar value of loss for crew member is very important as
both sts-107 & sts-51l lost the entire crew, so therefore a starting
point for cost estimating what value of "s" would represent reality
is at least amount of the dollars paid out in death benefits to the all
of the sts-107 crews families, plus an average cost for a crews
complete training from start to finish as this would represent the
investment of the tax payers into the flight crew. Obviously there are
more monetary costs involved with accurately calculating the costs for
the death of crew that I did not account for but let just take the
death benefits/crew training that I cited and adjust for inflation,
that would be a basis for "s" or death of a crew. Therefore the
revised cost equation that is a more accurately representation of the
real benefits and drawbacks associated with investing in our space
program safety improvements for a crit1 component would be how many
(x-s) dollars is society willing to spend to produce y amount of
reduced risk in order to provide that a shuttle crew be safer.
The crew's families are the ones who suffer the greatest, and a
perspective must be kept as to whom suffers when an orbiter crew is
lost. But those who are responsible for the space shuttle crew's
safety always have a hard time translating the missed opportunities of
the past such as funding for safety improvement that would
substantially reduce the risk of the loss of a crew. Post challenger
studies clearly demonstrated the qualitative determined failure mode
and effect analysis (FMEA) and the resulting critical items list (CIL)
for the orbiter program were under estimating the actual failure
probabilities (*9 "Criticality 1 CILs, such as hydrazine, were
overlooked in the component oriented FMEAs"). Nasa then prompted a
quantitative risk assessment of two systems the main engine propulsion
system, and the auxiliary power unit (apu). The apu is a hydrazine
fueled power plant than when the fuel is passed through a chamber a
combustive reaction occurs, providing the force to move the hydraulic
pump turbine blades. The power generated from the apu is translated
into providing pressure to the hydraulic system, where the hydraulic
fluid applies pressure to the various actuators that move the orbiters
critical flight control surfaces. The amount power generated by the
apu is directly correlated to the amount of force required to move the
orbiters critical flight control surfaces. The slay report determined
the risk analysis for the apu missed a 30% increase in failure
probability because the original fmea concentrated only on crit1
components. Replacement of the apu's with an electric apu (EAPU),
was determined to be a high priority and deemed a phase III upgrade
because of the required time to develop the necessary technology. But
the pace of investment into the new technology of the EAPU, determined
the amount of time the technology would take to mature, and in 2000
nasa had spent $650 million on the EAPU already, and another $100 to
$150 to complete the eapu, was weighed against the total amount to
maintain the current apu system operation through 2030 of about $350
million (*10). But nasa applied circular logic in the 2001 space
shuttle annual report in stating that due to funding and technology
advancement the EAPU project was deferred, but the EAPU technology
advancement was a direct function of how nasa prioritized and invested,
and therefore nasa determined the EAPU safety upgrade was not a high
priority (*11), reflected in nasa's 2003 budget request (*12).
Hindsight being 20/20 and in a post Columbia tragedy joint
congressional hearing on 2/12/03 administrator O'Keefe testified the
one safety upgrade he did not approve as administrator or at his
previous position at omb was the EAPU (*13). Inspite of repeated
recommendations nasa had decided a replacement for the current apu
system was too costly, but given the EAPU technology was to be
implemented by 2005 (*14) the investment would have currently made the
orbiter fleet safer for our flight crews for remaining 5 years until
fleet retirement in 2010. There is no way to determine the intrinsic
value for life, but in spite of the fact the information of the
underestimated risk associated with the current apu was in front of
nasa managers for almost two decades, the investment to make the crew
safer with an upgrade was determined not worth it by those inside nasa
who are responsible for crew safety, and development of the EAPU
stopped.
tom
**citations
(*1)
The feb 1995 Report of the space shuttle management independent review
team, or otherwise known as the Kraft report.
"The program, however, remains in a quasi-development mode and yearly
costs remain
higher than required. Given the current NASA-contractor structure and
incentives, it is
difficult to establish cost reduction as a primary goal and implement
changes to achieve
efficiencies. As a result, the team sought to create a management
structure and
associated environment that enables and motivates the Program to
further reduce
operational costs.
Accordingly, the review team concluded that the NASA Space Shuttle
Program should
(1) Establish a clear set of program goals, placing a greater emphasis
on cost-efficient
operations and user-friendly payload integration.
(2) Redefine the management structure, separating development and
operations and
disengaging NASA from the daily operation of the space shuttle.
(3) Provide the necessary environment and conditions within the
program to pursue
these goals...
The new management approach will require the following immediate
actions:
(1) Freeze the current vehicle configuration, minimizing future
modifications, with
such modifications delivered in bloc updates. Future bloc updates
should
implement modifications required to make the vehicle more re-usable and
operational.
(2) Perform a requirements review, top down, with the goal of
significantly reducing
checkout and other requirements based upon operations experience.
(3) Consolidate and reduce program and project elements, limiting NASA
involvement
in operations and minimizing NASA-contractor interfaces.
(4) Restructure and reduce the overall Safety Reliability and Quality
Assurance
(SR&QA) elements-without reducing safety.
(5) Streamline payload processing and integration, minimizing costs
and reducing the
length of time required to integrate a payload aboard the space
shuttle.
(6) Structure operational contracts to provide real incentive to
reduce costs while
accomplishing safe and successful missions.
(7) Allow the hiring of NASA personnel by the prime and subcontractors
to ensure
proper expertise and talents exist to continue with safe and successful
operations."
(*5)
annual report to the US nasa administrator by the aerospace safety
advisory panel
part II-space shuttle program june 1975
(*3)
NASA's Response to Comments made in the on the Space Shuttle Program
dated June, 1976 Aerospace Safety Advisory Pane1 Annual Report
(*4)
caib report vol 1 page 114 col 2 par 3
Responding to NASA.s concern that the Shuttle required safety-related
upgrades, the President.s proposed NASA budget for Fiscal Year 2001
proposed a "safety upgrades initiative." That initiative had a
short life span. In its Fiscal Year 2002 budget request, NASA proposed
to spend $1.836 billion on Shuttle upgrades over five years. A year
later, the Fiscal Year 2003 request contained a plan to spend $1.220
billion - a 34 percent reduction. The reductions were pri-marily a
response to rising Shuttle operating costs and the need to stay within
a fixed Shuttle budget. Cost growth in Shuttle operations forced NASA
to "use funds intended for Space Shuttle safety upgrades to address
operational, sup-portability, obsolescence, and infrastructure
needs." 64
(*5)
As the caib noted Caib report vol 1 page 188 col 2 par 8
"...Space Flight Leadership Council accepted the upgrades only as
long as they were financially feasible. Funding a safety upgrade in
order to fly safely, and then canceling it for budgetary reasons, makes
the concept of mission safety rather hollow."
(*6)
http://www.hq.nasa.gov/office/budget/fy96/hsf_3.html
HUMAN SPACE FLIGHT FISCAL YEAR 1996 ESTIMATES BUDGET SUMMARY
OFFICE OF SPACE FLIGHT SPACE SHUTTLE
"NASA has also reviewed and updated the Space Shuttle pricing policy
using data from the current budget submission. NASA and the Office of
Management and Budget (OMB) have agreed that the Space Shuttle flight
price would be based on recovery of average Space Shuttle operating
costs, which includes a portion of recurring safety and performance
upgrades. NASA is currently coordinating this flight price update
with its international Space Station partners.
BASIS OF FY 1996 FUNDING REQUIREMENT
SHUTTLE OPERATIONS
FY 1994 FY 1995
FY 1996
(Thousands of Dollars)
Orbiter and integration 586,900 528,200
504,900
(Orbiter) (387,900) (359,800)
(352,700)
(System integration) (199.000) (168,400)
(152,200)
Propulsion 996,000
1,006,997 993,200
(External tank) (252,200) (329,600)
(328,000)
(Space shuttle main engine) (189,200) (149,200)
(145,600)
(Redesigned solid rocket motor) (396,400) (365,997)
(355,400)
(Solid rocket booster) (158,200) (162,200) (164,200)
Mission and launch operations 966,100 880,100
896,700
(Launch and landing operations) (650,100) (626,400)
(612,100)
(Mission and crew operations) (316,000) (253,700)
(284,600)
Total 2,549,000 2,415,297
2,394,800
PROGRAM GOALS
The goal of Shuttle Operations is to provide safe, reliable, and
cost-effective access to space. Space Shuttle operations are
manifested at a planned rate of seven flights per year from FY 1995
through FY 2000.
The Space Shuttle program is aggressively continuing to significantly
reduce the cost of operations. Since FY 1992, cost reduction
efforts have been successful in identifying and implementing program
efficiencies and specific content reductions. Space Shuttle
project offices and contractors have been challenged to meet reduced
budget targets."
(*7)
http://www1.jsc.nasa.gov/bu2/hamaker.html
But What Will It Cost?
The History of NASA Cost Estimating
"New ideas on this topic abound. Total Quality Management, Design to
Cost, Concurrent Engineering and a number of other cultural changes are
being suggested as a solution to the problems of high cost. As usual,
the NASA estimating community is in the middle. Armed with data from
the past, which somehow must be adapted to estimate the future, they
attempt to answer the all important question: But what will it cost?"
(#8).
http://nodis3.gsfc.nasa.gov/displayAll.cfm?Internal_ID=N_PR_8705_002A...
Subject: Human-Rating Requirements for Space Systems NASA
Procedural Requirements NPR 8705.2A
Effective Date: February 07, 2005
Expiration Date: February 07, 2010
COMPLIANCE IS MANDATORY
"Responsible Office: Office of Safety and Mission Assurance
"B.42 Risk Assessment: An evaluation of a risk item that determines
(1) what can go wrong, (2) how likely is it to occur, and (3) what the
consequences are.
B.43 Safe Haven: A functional association of capabilities and
environments that is initiated and activated in the event of a
potentially life-threatening anomaly and allows human survival until
rescue or repair can be affected.
B.44 Safety: The freedom from those conditions that can cause death,
injury, occupational illness, damage to or loss of equipment or
property, or damage to the environment.
B.48 Test Flight: A flight occurring prior to certification."
(*9)
REVIEW OF RISK MANAGEMENT PRACTICES IN
VARIOUS ORGANIZATIONS AND INDUSTRIES
January 2000 By:
ERI Consulting & Co.
CH-6343 Rotkreuz Switzerland
Prepared for: European Space Agency
The European Space Research and Technology Centre (ESTEC)
Page 18
Challenger accident in January of 1986 changed most of their minds but
by no means all.
Some still clung to the belief that the accident was a "fluke" and
would never have happened if the shuttle had been launched within the
original launch envelope.
However, despite continued skepticism, since both the Rogers (1986) and
Slay (1988)
investigation teams had strongly encouraged NASA to undertake efforts
in quantitative risk assessment, two pilot studies were initiated in
1987. These two studies were focused upon single shuttle orbiter
systems: the Auxiliary Propulsion Unit or APU, and the Main Propulsion
Pressurization System. The former study was conducted by a joint
McDonnell Douglas and Pickard, Lowe, and Garrick team and was completed
in 1988 and the latter study was conducted by Lockheed with some
support from SAIC in 1989. While the studies were limited in their
scope, they showed particular weaknesses in the qualitative FMEA/CIL
approach. In particular, the APU study indicated that about 30% of the
risk was missed by concentrating on Criticality 1 CILs alone, and that
some of the major (in terms of probability contribution) Criticality 1
CILs, such as hydrazine, were overlooked in the component oriented
FMEAs."
(*10)
Upgrading the Space Shuttle
Committee on Space Shuttle Upgrades
Aeronautics and Space Engineering Board
Commission on Engineering and Technical Systems
National Research Council
NATIONAL ACADEMY PRESS Washington, D.C. 1999
http://bob.nap.edu/html/upgrading/
PHASE III UPGRADES
Replacement of the Auxiliary Power Unit
Each shuttle orbiter has three APUs, which are used to power the
vehicle's hydraulics during ascent and reentry. The APUs use hydrazine
propellant to drive a high-speed turbine that produces mechanical
power. The APUs pose a hazard because they use toxic fuel, and they
have experienced problems during testing and flight, including a fire
involving the hydrazine fuel after the landing of the STS-9 mission.
Existing APUs could support the shuttle program through 2014 at current
flight rates. After that (or earlier if flight rates increase) the APUs
will start to reach their 75 hour operational life limit, resulting in
shortages and requiring cannibalization of APU systems. In an exercise
to determine the long-term operational costs of the current APUs,
contractors estimated that the cost of keeping the current system
operational until 2030 would be approximately $550 million.
NASA is studying a number of options for replacing the APUs with an
electric system to support a decision in 2000 on proceeding with the
upgrade. NASA is now exploring different battery chemistries and
ultracapacitors to provide energy storage and peak power production.
Most of the electric systems under consideration would weigh slightly
more than the current APUs but would be less toxic. NASA has spent
about $650,000 so far, and total development and implementation costs
are estimated at $100 to $150 million. Total costs of developing the
system and operating it until 2030 are estimated to be about $350
million.
Few systems are more important to the safe operation of the shuttle
than the APUs. These flight-critical systems are essential for the
important launch and reentry phases; they involve high concentrations
of mechanical energy and a very toxic, corrosive, and combustible fuel;
and in spite of redundancy against single failures, they are spatially
vulnerable to common cause failures, such as fire, explosion, and
leaks. Not all of these vulnerabilities would be eliminated with the
proposed upgrade, but the very important vulnerability from chemical
energetics would be eliminated. In addition, the replacement of the
existing APUs by longer-life, less toxic, more efficient power units
would reduce turnaround time during ground processing of the orbiter
system.
In its search for a replacement for the APU, NASA can take advantage of
worldwide efforts to develop advanced electric power systems, including
aerospace applications (e.g., the Joint Strike Fighter, the F-22, the
Comanche helicopter, the X-33, and the X-34), as well as the
development of electric cars (by many companies, including Ford,
General Motors, Honda, Toyota, and Nissan). By learning from and
applying the technologies developed elsewhere, NASA could greatly
leverage its funding for development of a replacement for the APU.
However, considerably more study will be necessary to determine the
benefits and costs of the upgrade. Probabilistic risk analysis can be
used to estimate the safety impact of improving APUs and compare it
with other safety improvements. Further analysis can be performed to
determine more accurately the viability of other approaches to
upgrading the APUs (including purchasing additional spare parts for the
current APUs). Additional analysis is also warranted to determine
whether the hydrazine-driven units that power the solid rocket
booster's thrust vector control system (and which have similar problems
and concerns as the current APUs) should also be replaced as part of
the APU upgrade.
Recommendation 16. NASA should continue studying potential
modifications to the APUs to better determine the costs, benefits, and
appropriate scope of an upgrade. Developments in electric power systems
worldwide should be monitored to identify technologies and techniques
that could be useful for an APU upgrade. "
(*11)
2001 space shuttle annual report
page 14, col 1, par 2
"Excellent progress was also accomplished in defining, analyzing, and
planning
the proposed electric auxiliary power unit (EAPU) and solid rocket
booster (SRB) thrust vector control/auxiliary power unit (APU)
upgrades. Implementation of these two projects has been deferred due
to technical readiness of the EAPU and overall SSP funding
priorities."
(*12)
2002 NASA'S FISCAL YEAR 2003 BUDGET REQUEST HEARING BEFORE THE
COMMITTEE ON SCIENCE HOUSE OF REPRESENTATIVES ONE HUNDRED SEVENTH
CONGRESS SECOND SESSION FEBRUARY 27, 2002ANSWERS TO POST-HEARING
QUESTIONS
Responses to written questions submitted by Congressman Nick Lampson
resulting from the February 27, 2002, hearing Q3c. If the rationale is
that some of the safety upgrades money is needed for safety-related
infrastructure problems at the Cape and elsewhere, isn't that
equivalent to saying that you have decided to cannibalize one part of
the Shuttle safety program to help another part? Wouldn't the more
responsible action as Administrator be to increase the overall Shuttle
budget so that NASA doesn't have to choose which unsafe condition it is
willing to tolerate in the Shuttle program?
A3c. To stay within the President's FY 2003 budget plan, funds must be
balanced across the entire Agency. NASA has attempted to optimize the
Space Shuttle Safety Upgrades program for maximum safety benefit within
the time horizon, the amounts appropriated, and approved funding plans.
Q4a. One of the cancelled upgrades was the Electric APU project.
From the perspective of reducing total risks in the Shuttle
program, the Electric APU upgrade has been identified as having one of
the highest impacts on mission safety. If the upgrade is so critical in
terms of reducing overall risk to the Shuttle, why was it cancelled?
A4a. Today the Space Shuttle fleet is as safe to fly as we can humanly
make it prior to committing to each and every launch. Our commitment
remains to continually increase safety and reduce risk by implementing
high priority upgrades where technologically feasible. NASA determined
that the Electric Auxiliary Power Unit (EAPU) upgrade, while having
high potential for risk reduction, was not ready to proceed with
implementation due to technical immaturity in several areas. Some of
that technology may mature in the coming years under the Space Launch
Initiative (SLI). Should that occur and a replacement vehicle for
Shuttle still be unavailable, NASA may revisit the relative priority of
this upgrade.
Q4b. If it was cancelled because the technology wasn't advanced enough,
have you instituted a technology program to enable you to restart the
Electric APU program as soon as is feasible from a technical and
cost-fidelity standpoint?
A4b. There is a minor technology effort currently under way for FY
2002. This effort includes an EAPU Battery technology assessment
requirements reduction study, as well as project documentation to allow
for potential reuse at a later date. FY03 direction is dependent on
technical results from this year's activities, priority relative to
other potential investments and Program needs.
Q4c. If so, what is the annual funding budgeted for that technology
program, and when will you be able to restart the Electric APU effort?
A4c. There is a minor technology effort currently under way for $4
million in FY 2002. FY03 direction will be based on results from this
year's activities, priority relative to other potential investments and
Program needs.
Q4d. If not, why not, given the risk reduction potential of the
upgrade?
A4d. FY03 budget direction will be based on results from this year's
activities, priority relative to other potential investments and
Program needs. The results of this year's activities will not be
available until later this year. NASA is currently assessing potential
upgrades and supportability investments that may be required to
maintain the Space Shuttle fleet capability to fly safely through 2020,
and EAPU will be included in that assessment."
(*13)
JOINT HEARING WITH
SENATE COMMERCE, SCIENCE AND TRANSPORTATION COMMITTEE
and HOUSE SCIENCE COMMITTEE
ON COLUMBIA DISASTER AND THE FUTURE OF NASA
WASHINGTON D.C.
February 12, 2003
WITNESS: Sean O'Keefe NASA Administrator
U.S. Rep. Zoe Lofgren (D-CA) :But one of the questions I have for you,
administrator is as we look at what we should do to make sure that the
risks are minimized, were there any safety upgrade proposals ever made
to you, either as administrator or in your prior life over at the OMB,
that you did not support? And if so, what were those recommendations?
And why did you reach the conclusion that you did?
O'KEEFE: Not that I'm aware of. But I certainly will review the history
of both of my capacities in the course of this administration and
ascertain the dates of when there were any deferrals or anything else
of any upgrades that would be categorized as exclusively focused on
safety. So to my knowledge, we have not done so.
The only issues I am aware of is an electric auxiliary power unit
upgrade that had been planned that was determined to be technically
deficient and wasn't--so in other words, no amount of money we threw at
it was going to yield its performance in the manner in which it would
contribute to not only efficiency, but also safety
characterization--that was deferred and we're now reexamining to figure
out how we can pick that up or continue it in the future that would
yield the performance requirements we know of.
But we will go back. And I will submit for the record any other changes
that were made during the course of--well, since Inauguration Day,
2001. And if there are any changes that have occurred in that time, we
will certainly report those.
LOFGREN: So you will go back and review the record and take a look at
your--obviously, hindsight is 20/20 and we're all doing that in terms
of our own activities--what you recommended, both at OMB and in your
role as NASA administrator.
O'KEEFE: I'll do my best.
LOFGREN: Thank you very much. And my time is up, Mr. Chairman."
(*14)
GAO/NSIAD/GGD-00-186 Space Shuttle Human Capital Challenges
Page 19
"Appendix II
Space Shuttle Upgrades Appendix II
NASA has identified a set of potential shuttle upgrades to be
incorporated by fiscal year 2005. The program includes potential
improvements to every major area of the shuttle system. A breakout of
the planned modifications is shown in table 1. Table 1: Potential Space
Shuttle Upgrades Dollars in millions Upgrade area Purpose of upgrade
Estimated cost Electric auxiliary power Unit Eliminates use of
hazardous fuel and high-speed equipment to generate power for the
orbiter's hydraulic system $224.0 Solid rocket booster auxiliary power
unit Eliminates the use of hazardous fuel in the solid rocket booster
thrust vector control auxiliary power unit $208.0"
Malcolm Bacchus wrote:
In article <1152768103.951177.77160@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
columbiaaccidentinvestigation@xxxxxxxxx (columbiaaccidentinvestigation)
wrote:
*From:* "columbiaaccidentinvestigation"
<columbiaaccidentinvestigation@xxxxxxxxx>
*Date:* 12 Jul 2006 22:21:43 -0700
My conclusion and writings to make safety the highest priority in our
space program are not trivial nor in jest,
They are not trivial; I can see they are not in jest. But they are
meaningless and unworkable unless you can put a specific costable safety
factor on lives.
To make a trivial example let us say the priorities were:
1. Safety
2. Cost
How do you evaluate this if you are told by engineering that you can
reduce the chance of a death in the programme by a further 0.01% at the
cost of $1bn?
If then you decide that safety is the absolute number 1 priority, and
you are told Congress won't grant an extra $1bn, you won't fly, yes?
Now replace $1bn by $10bn. How does you analysis now work?
How does it work if the reduction in risk was 0.000001%?
Unless there is a 100% chance of safety, there will always be an amount
X which you could spend which will reduce the chance of risk slightly.
So how much can you spend?
Time is always another constraint. You could see if you could meet the
annual budget constraints and your requirement for safety another way -
you could stretch the programme out over more years (provided that did
not increase the safety risk another way) or simply wait until the
safety technology you need becomes available. But that may never
happen. So how long do you wait?
In practice, safety is always hedged around by these constraints. What
you do is to work out what you can do within those constraints and THEN
decide whether you have reduced the risk to an acceptable, but not
minimal level. If you haven't you go back and do it again or give up
(depending on the constraints); if you have, you launch.
But you still have to decide on the acceptable level of risk and merely
saying "safety is the number priority" cannot absolve management of
making that call. So my last questin - what, in your judgement, is that
level of risk?
Malcolm B
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