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Brooks 1987, Computer Software is such that it is unlikely that the problem of creating it will go away Software is Essentially ComplexoProblem complexity Primality of social complexity Change Unvisualizable Control Data Dependency Time Name space*HZ(ZH(, ): Breakthroughs not EssentialD HLL s elevate level of solution mechanism NOT decrease in problem complexity OO removes  accidental complexity ADT hides complexity Hierarchy allows refinementL+#$1+#$1Contra SpecificsAI Heuristic programming Direct application to software tasks (why not expression of problem  KRR) Automatic programming Only well-defined problems solved (learning when already almost know - KRR) Graphics No/little SE content (some problem solving (E.g. geometry  KRR)ZZKZZLZ ZZ,Z%&" *  , HopesMass market Improved cost/benefit ratio Social acceptance of phenomena Requirements refinement & rapid prototyping Tangible representation Early aggreementL <,) <,)  & Quotes in Summaryz  No silver bullet for software  Software is complex, conforming, changeable and invisible  Software technologies overcome the accidental problems  Most important SE service is analysis   Commentary Separate domain from system complexity Domain Functional Environmental Social Physical System Parts complexity Production complexityv''' ' Domain Complexity ExamplesDomain Complexity CS1 problems very low Calculator low Database moderate Aircraft flight system moderately high Aircraft controller system high SDI astronomical Learning higher still&   Some Systems Residual Complexity Complexity is Fuzzy & DynamicFunction interacts with Environment Physical Social These are not be static in most cases Function is (almost) unbound  anything , however complex, can be programmed Function is malleable  easy to customizeZ ZZ&ZZ/ZZZ &  / ` ` ̙33` 333MMM` ff3333f` f` f` 3>?" dd@,|?" dd@   " @ ` n?" dd@   @@``PR    @ ` ` p>> (    6 "  T Click to edit Master title style! !$  04 "`  RClick to edit Master text styles Second level Third level Fourth level Fifth level!     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E 1  O Very high   @` !0 <8h?HE  1  O Very high   @` 0 <:h?E H1  ISDI @` 0 <Ph?1  MUnbound @` 0 <0Yh? 1  MUnbound @` 0 <Rh?H1   MUnbound @` 0 <jh?1 H I??? @` 0 <qh?E  ILow @` 0 <zh? E  NModerate   @`  0 <{h?H E  NModerate   @`  0 <h?HE  XAccounting program @`  0 <h?v ILow @`  0 <lh? v ILow @`  0 <h?Hv  ILow @` 0 <Эh?vH P Calculator   @` 0 <h?v YPhysical Complexity @` 0 <ܾh? v WSocial Complexity @` 0 <h?H v [Functional complexity @` 0 <h?Hv LSystem @``B 0 0o ?ZB 0 s *1 ?vvZB 0 s *1 ?ZB 0 s *1 ?E E `B 0 0o ?`B 0 0o ?ZB 0 s *1 ?HHZB 0 s *1 ?  ZB 0 s *1 ?`B 0 0o ?ZB  0 s *1 ?1 1 H 0 0޽h ? ̙33   -N4-(  4r 4 S h  h  h p 54 #" Sp $4 <|h?p PSoftware   @` "4 <\h? YSystem Complexity @`  4 <h?@p KMax @`  4 <h? @p Q Moderate+   @`  4 <j?  p PModerate   @` 4 <H j? p KLow @` 4 <pj?@ XMachine language @` 4 <d!j? @ [Procedural language @` 4 <|#j?   S OO language   @` 4 <j?  ZComponent assembly @``B 4 0o ?ZB 4 s *1 ?`B 4 0o ?pp`B 4 0o ?pZB 4 s *1 ?  pZB 4 s *1 ?  pZB 4 s *1 ?@@p`B 4 0o ?pZB #4 s *1 ?p  4 <8j \Consider Software Calculator$  A h  P  M4 #" S P  74 <Cj ? P  PSoftware   @` 84 <Lj ?   YSystem Complexity @` 94 < Vj ?@ P  KMax @` :4 <Wj ?P @P  ^ Moderate10"   @` ;4 <Tij ? P P  PModerate   @` <4 <qj ? P  KLow @` =4 <`{j ?@   R Mechanical   @` >4 <h}j ?P @  S Transistors   @` ?4 <j ? P  MChips @` @4 <Жj ?  ZComponent assembly @`fB A4 6o ?  `B B4 01 ?  fB C4 6o ?P P fB D4 6o ? P `B E4 01 ? P `B F4 01 ?P P P `B G4 01 ?@ @P fB H4 6o ? P `B I4 01 ? P  J4 < j  \Consider Physical Calculator$  x N4 <j0,$D 0 Problem complexity is what s left after most economical, realizable theory. $MKAH 4 0޽h ? ̙33___PPT10+mEFDO' = @B D ' = @BA?%,( < +O%,( < +DA' =%(D' =%(D' =A@BBBB0B%(D' =1:Bvisible*o3>+B#style.visibility<*N4%(+8+0+N4j +  8$(  8r 8 S xjj `  j r 8 S j` j H 8 0޽h ? ̙33r@wY[$G&3(* ,-/13:PgqeSsOh+'0 hp  4 @ LX`No Silver BulleteKRRIGGSPC:\Documents and Settings\a\Application Data\Microsoft\Templates\ClassNotes.pot Ken R Riggs2n Microsoft PowerPointing@ @OoI@@p_):GBg    --$--'@Times New Roman-. 2 U6/8/2006   ."System-@Times New Roman-.  2 1 .-@Times New Roman-. 332 O%No Silver Bullet,"*".--33-\V%--@Times New Roman-. 2  Dr. Riggs   .-@Times New Roman-. 2 w Summer 2006u"" .-՜.+,0    lOn-screen Show famuees~ O Times New Roman Arial Narrow ClassNotesNo Silver BulletNo Silver Bullet Software is Essentially ComplexBreakthroughs not EssentialContra SpecificsHopesQuotes in Summary CommentaryDomain Complexity Examples Some SystemsResidual ComplexityComplexity is Fuzzy & Dynamic  Fonts UsedDesign Template Slide Titles #_s )Ken R RiggsKen R Riggs  !"#$%&'()*+,-./0123456789;<=>?@ACDEFGHIKLMNOPQTRoot EntrydO)Current UserJSummaryInformation(:PowerPoint Document(sDocumentSummaryInformation8B