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SYSTEMSENGINEERING ANDTHE SOFTWARELAWS OFTHERMODYNAMICS
SYSTEMSENGINEERING ANDTHE SOFTWARELAWS OFTHERMODYNAMICS
Dr. Thomas F. Christian Jr.Director of Engineering
ACSSW, WPAFB OH26 Oct, 2005
Dr. Thomas F. Christian Jr.Director of Engineering
ACSSW, WPAFB OH26 Oct, 2005
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SYSTEMS ENGINEERING
• Systems Engineering is thedisciplined application of tools andprinciples to achieve a complex goal
• Software Engineering is part ofSystems Engineering
• Systems Engineering must obey theFundamental Laws of Physics
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THE LAWS OF PHYSICS
• But what are the fundamental lawsof physics?
• F=MA?
• Earlier seminal work at SSTC 2005said “Yes” – Newton’s Laws ofMotion govern Software Engineering
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THE LAWS OF METAPHYSICS
• “I think therefore I code”
• No, No!!
• Even EEs understand Inertia but,could there be some law even morefundamental than that?
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-- YES --
THERMO
The unexplainable
THE LAWS OF NATURALPHILOSOPHY
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1ST LAW – CONSERVATIONOF ENERGY
“If the state of a system is changedby applying work or heat or both,
then the change in the energy of thesystem must equal the energy
applied”
T1
(HOT)
T2
(COLD)
Heat TransferQ
S = Entropy =Q
T
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“It is impossible to move heat, bycyclical process from something atlower temperature to something athigher temperature unless work is
added to the system”
2nd LAW – TENDENCYTOWARD EQUILIBRIUM
EACT
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“If the entropy of each element atabsolute zero can be taken as zero,
then all elements above absolute zeromust have a finite, positive entropy;however, because entropy cannot be
reduced to zero by finite means (as perthe Second Law), no system can reach
absolute zero”
3rd LAW – ABSOLUTE ZERO
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Since we are Systems Engineers- Not Physicists –
Let’s put them into SystemEngineering - Speak
• 1st Law: You Can’t Win – JustBreak Even
• 2nd Law: You Can Only Break Evenat Absolute Zero
• 3rd Law: You Can’t Reach AbsoluteZero
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THE SOFTWARE LAWS OFTHERMODYNAMICS
• Optimizing software quality, cost,schedule require proper processes,planning, and people
• Proper processes, planning andpeople requires time to do it right
• There is NEVER time to do it right
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“RASSA’S LAW”
• “No one can resist the temptation toedit another’s work or start codingon the first day of a program”
