Rethinking Technical Debt

lٕज़తෛ࠴z Λ໰͍ͳ͓͢

ࣗݾ঺հ w ܀ྛ݈ଠ࿠ w !LFOUBSP BOUJQPQ ͋ΜͪΆ w ιϑτ΢ΣΞΤϯδχΞ w
גࣜձࣾQBQFSCPZDP w ٕज़ج൫νʔϜɺάϩʔενʔϜ

ࣗݾ঺հ

໰୊ҙࣝ w ͍ΘΏΔlٕज़తෛ࠴zʹ͍ͭͯɺ᷿ؒग़ճ͍ͬͯΔ ݴઆ͸ɺ ྺ࢙త ൺᄻత ࣮ફతʹෆे෼ͳ
ೝࣝʹ΋ͱ͍͍ͮͯΔ w ͦͷͨΊɺ౰ॳͦͷ༻ޠ͕৽઱ͳ΋ͷͱͯ͠ಋೖ͠ ͨ͸ͣͷೝࣝརಘ͕ᆝଛ͞Εɺ͍·΍୯ͳΔਫֻ͚ ࿦Λؒᓛతʹऒى͢Δͷʹ࢖༻͞ΕΔ͹͔Γͩ w ຊτʔΫͰ͸ɺ౰֘༻ޠͷຊٛʹཱͪฦΓɺ͞Βʹ ద੾ͳઆ໌Λఏڙ͢Δ͜ͱͰɺΑΓΑ͍ݴઆͷج൫ Λఏڙ͢Δ

ྺ࢙

lٕज़తෛ࠴zͷىݯ lίʔυΛॳΊͯ֎ʹग़͢ͷ͸ɺआۚ ༁ḼEFCU Λ ͠ʹߦ͘Α͏ͳ΋ͷͩɻॻ͖௚͠ʹΑΓͦΕ͕͙͢ʹ ฦ͞ΕΔݶΓʹ͓͍ͯ͸ɺ։ൃεϐʔυ͕ૣ·ΔɻΦ ϒδΣΫτࢤ޲͸ɺͦͷίετΛڐ༰Մೳͳ΋ͷʹ͢ ΔͩΖ͏ɻةݥͳͷ͸ɺआ͕ۚฦ͞Εͳ͍࣌ͩɻਖ਼͠ ͍ͱ͸͍͑ͳ͍ίʔυʹඅ΍࣌ؒ͢͸ɺआۚͷརࢠͷ Α͏ͳ΋ͷɻΤϯδχΞϦϯάΛͱ΋ͳ͏૊৫͸͢΂
ͯɺ͙͙ͩͩͳ࣮૷͕΋ͨΒ͢आۚͱ͍͏΂͖ॏՙʹ Αͬͯɺ଍ࢭΊΛ͘Θ͞ΕΔ͜ͱʹͳΓಘΔɻz $VOOJOHIBN

lٕज़తෛ࠴zͷىݯ w 8BSE$VOOJOHIBNʹΑͬͯɺ೥ʹఏى ͞Εͨ $VOOJOHIBN w 8JLJͷൃ໌ऀ w
F9USFBN1SPHSBNNJOHͷओএऀ

lٕज़తෛ࠴zͷىݯ w lෛ࠴zͱ͍͏ൺᄻͷಋೖ w lෛ࠴zͦͷ΋ͷ͕ѱ͍Θ͚Ͱ͸ͳ͍ w lฦࡁz͑͞ద੾ʹ͞ΕΕ͹ɺϓϩδΣΫτΛεϐʔ υΞοϓͰ͖Δͱ͍͏͍͍໘͕͋Δ w ͨͩ͠ɺͦΕΛฦࡁͤͣʹ์ஔͨ͠৔߹ʹ໰୊͕ى
͜Δ

lٕज़తෛ࠴zͷ෼ྨ l8BSE͸ͦͷൺᄻ ༁ḼEFCUͷ͜ͱ Λਂ͘·Ͱ۷ ΓԼ͛Δ͜ͱ͸ͳ͔ͬͨɻٕज़తෛ࠴ʹ͍ͭͯٞ࿦͠ ͖ͯͨਓʑ͸ɺओʹٕज़ऀͨͪͱίϛϡχέʔγϣϯ ͢ΔͨΊʹͦͷൺᄻΛ͔͍ͭͬͯΔΑ͏ͩɻͦΕ͕ٕ ज़ऀͨͪͱͷίϛϡχέʔγϣϯʹ༗༻ͳൺᄻͰ͋Δ ͜ͱʹɺࢲ͸ಉҙ͢Δɻ͔͠͠ɺΑΓࢲ͕ڵຯΛ࣋ͬ ͍ͯΔͷ͸ɺॏཁͳٕज़తίϯηϓτΛɺٕज़ऀͰͳ
͍ϓϩδΣΫτͷεςʔΫϗϧμʹઆ໌͢Δʹ͋ͨͬ ͯɺͦͷൺᄻ͕৴͡೉͍΄Ͳ๛͔ͳදݱྗΛ΋͍ͬͯ Δͱ͍͏͜ͱͩɻz .D$POOFMM

lٕज़తෛ࠴zͷ෼ྨ w 5ZQF*௿඼࣭ͳ࢓ࣄʹΑΔɺҙਤ͠ͳ͍΋ͷ w 5ZQF**ҙਤతʹબ୒͢Δ΋ͷ w **"ઓज़తʹબ୒͞ΕΔ୹ظతͳ΋ͷ w **"ݸผʹࣝผՄೳ ྫࣗಈंϩʔϯ
w **"ଟྔͰࡉ͔͍ ྫΫϨδοτΧʔυ w **#ઓུతʹબ୒͞ΕΔ௕ظతͳ΋ͷ .D$POOFMM

lٕज़తෛ࠴zͷ෼ྨ ҙਤత ඇҙਤత ୹ظత ݸผత 5ZQF**" 5ZQF* ޒ݄Ӎత 5ZQF**" ௕ظత
5ZQF**# .D$POOFMM ྘৭͸ڐ༰ՄೳͳλΠϓͷlෛ࠴z

lٕज़తෛ࠴zͷ࢛৅ݶ w ϦνϟʔυɾϑΝ΢ϥʔɺ೥ʹlٕज़తෛ࠴z ʹݴٴ 'PXMFS֯ w lٕज़తෛ࠴zͷ࢛৅ݶΛఏএ 'PXMFS֯
w ͋Δ΋ͷ͕lෛ࠴zͰ͋Δ͔ͦ͏Ͱͳ͍͔ʹ͸͋· Γҙຯ͕ແ͍ w ͦͷݴ༿ͷಋೖʹΑΓɺઃܭ্ͷ໰୊ʹ͍ͭͯ஌ ݟΛಘΒΕΔ͔Ͳ͏͔ɺίϛϡχέʔγϣϯ͕ଅ ਐ͞ΕΔ͔Ͳ͏͔͕େࣄ w ίϛϡχέʔγϣϯͷͨΊͷ෼ྨ

lٕज़తෛ࠴zͷ࢛৅ݶ ແమ๒ͳ 3FDLMFTT ༻৺ਂ͍ 1SVEFOU ҙਤతͳ %FMJCFSBUF ઃܭ͢Δ͕࣌ؒͳ͍Μͩ ͔Β͠ΐ͏͕ͳ͍ ࠓ͙͢ϦϦʔε͠ͳ͍ͱ
͍͚ͳ͍ɻ ϦεΫ͸ঝ஌ͷ্ͩ ແҙࣝͳ *OBEWFSUFOU ϨΠϠʔԽʁ ͳʹͦΕʁ Α͠ɺ ͜ΕͰΦοέʔʂ 'PXMFS֯

lٕज़తෛ࠴zͷىݯɺ࠶ͼ w ଟ͘ͷਓʑ͸lٕज़తෛ࠴zΛޡղ͍ͯ͠Δ $VOOJOHIBN w ։ൃͷεϐʔυΞοϓͷͨΊʹμϝͳίʔυΛॻ ͍ͯ΋͍͍ͳͲͱ͸͍͍ͬͯͳ͍ w
ιϑτ΢ΣΞΛॻ͍ͨͦͷ࣌ΑΓ΋ਐΜͩཧղΛɺ ͋ͱ͔Β൓өͤ͞ΒΕΔͱ͍͏࿩ w ͦͷͨΊʹ΋ɺϦϑΝΫλϦϯάͰ͖ΔΑ͏ΫϦʔ ϯͳίʔυʹ͓ͯ͘͠ͷ͕େ੾

͜͜·Ͱͷ·ͱΊ w ద੾ʹฦࡁ͞ΕΔ෼ʹ͸ɺ։ൃͷεϐʔυΞοϓͱ͍͏ҙ ຯͰ͸ɺΉ͠Ζ๬·͍͜͠ͱͰ͢Β͋ΓಘΔ w lٕज़తෛ࠴z͸ɺٕज़ऀؒͷΈͳΒͣɺඇٕज़ऀͱͷؒͰ ͷίϛϡχέʔγϣϯʹ໾ཱͭൺᄻͰ͋Δ ΂͖ w
ͦͷͨΊʹɺͲ͏͍͏lෛ࠴z͕͋Δͷ͔Λ෼ྨɾ੔ཧ͢Δ w ·ͣɺҙਤత͔ඇҙਤత͔Ͱ෼ྨͰ͖Δɻ࣍ʹɺແమ๒ʹ ߦΘΕ͔ͨ༻৺ਂ͘ߦΘΕ͔ͨʹ෼ྨͰ͖Δ w ͦ΋ͦ΋͜ͷൺᄻ͸ʮμϝͳίʔυʯΛҙਤతʹॻ͘͜ͱ Λࢧ࣋͢Δ΋ͷͰ͸ͳ͍ɻͦ͏Ͱ͸ͳ͘ɺ͋ͱͰϦϑΝΫ λϦϯάͰ͖Δͱ͍͏ೝ͕ࣝେࣄ

ཧ࿦

ۙ೥ͷlٕज़తෛ࠴z࿦ w lෛ࠴ͷ෼ྨֶz͸ɺաڈͷग़དྷࣄΛ੔ཧ͢ΔͨΊ ͷ΋ͷ w ҙਤʹجͮ͘෼ྨ͸ɺաڈʹىͬͨ͜Ͱ͖͝ͱʹͭ ͍ͯͷίϛϡχέʔγϣϯʹͱͬͯ༗༻Ͱ͋Δʹ͠ ͯ΋ɺকདྷͷ։ൃʹର࣮ͯ࣋ͭ͠ફతܖػ͕ബ͍ w Ͳ͏͍͏৔߹ʹɺͲ͏͍͏ҙਤΛ࣋ͭͷ͕ద੾ͳͷ
͔͕Θ͔Βͳ͍ w ۙ೥ɺબ୒͞ΕΔศٓͱͯ͠Ͱ͸ͳ͘ɺҙਤΛ໰Θ ͳ͍lෛ࠴zͷϞσϦϯάͷࢼΈ͕ͳ͞Ε͍ͯΔ

ݟ͑ͳ͍΋ͷͱͯ͠ͷlෛ࠴z w ,SVDIUFOΒʹΑΔݚڀ ,SVDIUFOFUBM w ίʔυͷ඼࣭ͳͲͷΑ͏ͳՄࢹతͳlෛ࠴zΑΓ΋ Ή͠ΖɺΞʔΩςΫνϟతͳݟ͑ͳ͍lෛ࠴z͕ক
དྷͷ։ൃʹؔ͢Δҙࢥܾఆʹ΋ͨΒ͢Өڹʹண໨ w ҙࢥܾఆͷཁҼΛɺओʹকདྷͷ։ൃίετʹஔ͘ w ϑΝΠφϯεʹ͓͚Δ༷ʑͳϞσϧ͕ɺٕज़తͳҙ ࢥܾఆʹ͓͍ͯ༗༻Ͱ͋ΓಘΔ

ݟ͑ͳ͍΋ͷͱͯ͠ͷlෛ࠴z ݟ͑Δ 7JTJCMF ݟ͑ͳ͍ *OWJTJCMF ϓϥεͷՁ஋ 1PTJUJWF 7BMVF ৽ػೳ /FXGFBUVSFT
BEEFE GVODUJPOBMJUZ ΞʔΩςΫνϟɾߏ଄ "SDIJUFDUVSBM TUSVDUVSBM GFBUVSFT ϚΠφεͷՁ஋ /FHBUJWF 7BMVF όά %FGFDUT ٕज़తෛ࠴ 5FDIOJDBMEFCU ,SVDIUFOFUBM

ݟ͑ͳ͍΋ͷͱͯ͠ͷlෛ࠴z w কདྷͷ։ൃʹؔ͢Δҙࢥܾఆʹ͍ͭͯɺl΍Γ௚͠ 3FXPSL z ͱ͍͏؍఺ͰϞσϧԽ w ΞʔΩςΫνϟͷ࠶ߏங w ϦϑΝΫλϦϯά
FUD w ҙࢥܾఆཁҼ w Ͳͷ࣌఺ͰΞʔΩςΫνϟΛվળ͢Δ͔ ࠷ॳʹ΍Δ͔ɺ͋ ͱʹ΍Δ͔ w ͦͷ͜ͱ͕݁ՌతʹશମͷίετʹͲ͏Өڹ͢Δ͔ w ໨ʹݟ͑Δ΋ͷ ϢʔβՁ஋΍όάͳͲ ͱɺ໨ʹݟ͑ͳ͍Ξʔ ΩςΫνϟΛ෼͚ͯߟ͑Δ w ৄࡉ͸ /PEFFUBM ࢀর

Մೳత୅ସγεςϜͱͷࠩҟ w ,MBVT4DINJEʹΑΔݚڀ 4DINJE w lෛ࠴zͷཁҼ΍ҙਤΛ໰Θͳ͍ϞσϧԽ w Մೳత୅ସγεςϜͱͷࠩҟΛ໰͏

Մೳత୅ସγεςϜͱͷࠩҟ

Մೳత୅ସγεςϜͱͷࠩҟ w ݱ࣮తʹՄೳͳ୅ସγεςϜͱ͸Կ͔ʁͱ͍͏ࢹ఺ ΛಋೖͰ͖Δɻͨͱ͑͹ w Α͘੔උ͞Εͨ3BJMTΞϓϦ w 1VQQFU΍$IFGͰ͖ͬͪΓߏ੒؅ཧ͞Εͨαʔ ό܈ w
ͦ͏ͨ͠γεςϜͱͷࠩҟ͕ɺະདྷʹ͋ΓಘΔ։ൃ εςοϓʹ͓͍ͯͲͷΑ͏ͳӨڹΛ΋ͨΒ͠ಘΔͷ ͔ʹΑͬͯɺlෛ࠴ฦࡁzͷҙࢥܾఆΛߦ͏ w ৄࡉ͸ 4DINJE ࢀর

ҙਤΛ໰Θͳ͍Ϟσϧͷؚҙ w ͍͔ͳΔҙਤ͕͋Ζ͏ͱ΋ɺະདྷͷෆ࣮֬ੑͷલͰ ͸ଟ͔Εগͳ͔Εlෛ࠴z͸ආ͚ΒΕͳ͍ w ͋ΓಘΔະདྷͱɺͦͷະདྷʹ͓͍ͯՄೳͳબ୒ࢶͱ ͷؒͰɺͰ͖Δ͚ͩϚγʹݟ͑Δ΋ͷΛɺͦͷ࣌ͷ શྗΛਚͯ͘͠બΜͰ͍͔͘͠ͳ͍ w ͦ͏ͨ͠ࣄଶΛهड़͠ɺҙࢥܾఆʹد༩ՄೳͳϞσ
ϧͷํ͕ɺաڈͷlҙਤzͷ෼ྨֶΑΓ͸ز෼͔Ϛ γ

ൺᄻ

lෛ࠴zͱ͍͏ൺᄻͷ໰୊ w ࡒ຿ձܭతͳҙຯʹ͓͚Δෛ࠴ͱҟͳΓɺఆྔԽ͕ ࠔ೉ w ඞͣฦࡁ͠ͳ͚Ε͹ͳΒͳ͍ͱ͍͏΋ͷͰ͸ͳ͍ w ͦ΋ͦ΋୭͔͔ΒԿ͔ΛआΓ͍ͯΔೝ͕ࣝͱ΋ͳͬ ͍ͯͳ͍͜ͱ͕Α͋͘Δ w
lٕज़తෛ࠴zʹ͍ͭͯΑ͘ೝࣝ͠ɺద੾ʹରԠͯ͠ ͍ͯ΋ɺ࣌ؒͷܦաͱͱ΋ʹlෛ࠴Խz͕ى͜Δ w ίϛϡχέʔγϣϯʹ͓͚ΔศٓͷͨΊͷͷͨͱ͑ ࿩ͷ͸͕ͣɺͻͱΓา͖ͯ͠͠·͏

ෛ࠴ͱ͸ʁ w ʢҰൠతͳ༻๏ʣआۚͳͲɺଞਓ͔Βۚમ΍෺ࢿΛ आΓΔ͜ͱɻ͋Δ͍͸आΓͨۚમ΍෺ࢿͷ͜ͱɻ w ʢاۀձܭ༻ޠʣকདྷతʹɺଞͷܦࡁओମʹରͯ͠ɺ ۚમͳͲͷܦࡁతࢿݯΛҾ͖౉ٛ͢຿ͷ͜ͱɻ 8JLJQFEJBʮෛ࠴ʯ

͋͑ͯൺᄻΛ͞Βʹԡ͠޿͛Δ w ͨͩ͠ɺࡒ຿ձܭతͳҙຯʹ͓͚Δlෛ࠴zͷؚҙΛ ਖ਼͘͠ཧղͯ͠࢖͑͹ɺ༗༻ͳ΋ͷͱͳΓಘΔ w ϑΝΠφϯεͱձܭ͸ɺϏδωεʹ͓͚ΔϦϯΨɾ ϑϥϯΧ $POSPZ
w ෆ࣮֬ੑͷݩͰͷҙࢥܾఆϓϩηεʹ͍ͭͯ͸ɺܦ ࡁֶ΍ϑΝΠφϯεʹ͓͍ͯ஝ੵ͕͋Δɻͦ͏ͨ͠ Ϟσϧ͕໾ʹཱͪಘΔ ,SVDIUFOFUBM w lෛ࠴zͱ͍͏ൺᄻͷՄೳੑΛɺ΋͏গ͠ԡ͠޿͛ͯ ΋Αͦ͞͏ͩ

8FCαʔϏε։ൃͱׂҾ཰ w lٕज़తෛ࠴zΛɺϑΝΠφϯεʹ͓͚ΔׂҾ཰ͷ ໰୊ͱͯ͠ߟ࡯͢Δ ܀ྛ w 8FCαʔϏε։ൃʹ͓͚ΔҙࢥܾఆཁҼ w
ಘΒΕΔՁ஋Λ૿େͤ͞Δ w අ΍͞ΕΔίετΛݮগͤ͞Δ w Ձ஋Λ૿େͤͭͭ͞ɺίετΛݮগͤ͞Δ w ܧଓੑ͕͍ͭͯ·ΘΔ8FCαʔϏε։ൃʹ͓͚Δ lίετzͷࢉग़ʹ͸ɺׂҾ཰ΛצҊ͢Δ͜ͱ͕ඞ ਢɻ໰୊͸ͦͷόϥϯε

8FCαʔϏε։ൃͱׂҾ཰ 0 55 110 165 220 2014 2015 2016 2017
2018 ݱ࣮త(੒௕཰10%) ཧ૝త(੒௕཰20%) ͜ͷ෦෼͕ lٕज़తෛ࠴z ͱͳΓಘΔ

8FCαʔϏε։ൃͱׂҾ཰ 0 55 110 165 220 2014 2015 2016 2017
2018 ݱ࣮త(੒௕཰10%) ཧ૝త(੒௕཰20%) ͔͜͜Β ݟΕ͹ རࢠˠ ͔͜͜Β ݟΕ͹ ˡׂҾ཰

ΪϟοϓΛຒΊΔ w ཁٻ͞ΕΔ੒௕཰ͱɺݱ࣮తͳ੒௕཰ͱͷΪϟοϓ ΛɺͳΜΒ͔ͷํ๏ʹΑΓຒΊΔඞཁ͕͋Δ w ͦͷͨΊͷ͍ͪख๏ͱͯ͠ͷlෛ࠴z w ͦΕࣗମͷධՁʹ͸ಓಙతՁ஋൑அͳͲհࡏ͠ಘͳ ͍ɻޮՌʹ͓͍ͯͷΈ൑அ͞ΕΕ͹Α͍ w
Ұํɺlෛ࠴ଞਓࢿຊz͕͋ΔͳΒlࣗݾࢿຊzʹ ͍ͭͯߟ͑ͯ΋Αͦ͞͏ͩ w ιϑτ΢ΣΞ։ൃʹ͓͚Δlࣗݾࢿຊzͱ͸Կ͔ʁ ͦͷௐୡίετ͸Ͳ͏ܾ·Δͷ͔ʁ

ࢿຊௐୡίετ ੪౻

ࢿຊߏ੒ઓུ ιϑτ΢ΣΞ ࢿ࢈ ٕज़త lෛ࠴z ٕज़త lࢿຊz ιϑτ΢ΣΞ ࢿ࢈ ٕज़త
lෛ࠴z ٕज़త lࢿຊz ιϑτ΢ΣΞ ࢿ࢈ ٕज़త lෛ࠴z ٕज़త lࢿຊz ઓུ ࣌ؒ

࣮ફ

యܕతͳޡղ l։ൃऀ͸ɺ৽͍͠ػೳΛͭͷҟͳΔํ๏Ͱ࣮૷͢Δ ͜ͱΛબ୒Ͱ͖·͢ɻͭ͸ૉૣ͍͍͘Ճݮʹ࣮૷͠· ͢ɻ͜ͷ৔߹ɺকདྷͷมߋ͕ͱͯ΋೉͘͠ͳΓ·͢ɻ΋ ͏ͭ͸ɺΫϦʔϯͰεϚʔτͳղܾࡦͰ͋Γɺ࣮૷ʹ ͕͔͔࣌ؒΓ·͕͢ɺকདྷɺ؆୯ʹมߋͰ͖·͢ɻ .BSUJO'PXMFSΛ͝ཡԼ͍͞ɻ ͔͠͠ɺػೳΛΫ Ϧʔϯͳ࣮૷ʹͯ͠ɺΑΓଟ͘ͷίετΛ͔͚Δ͜ͱΛɺ ϓϩδΣΫτͷεϙϯαʔ͕ड͚ೖΕΔͰ͠ΐ͏͔
͍ ͍ՃݮͳղܾࡦͰಉ͡ػೳΛɺಉ༷ͷػೳੑΛ࣋ͨͤͨ ··ɺΑΓগͳ͍ίετͰఏڙͰ͖ΔͷͰ͢ɻz +PIBOO8PMGGେా

Կ͕ޡղͳͷ͔ w ෆ࣮֬ͳະདྷ΁޲͚ͨ։ൃΛɺҙਤ௨Γʹίϯτϩʔ ϧՄೳͳɺෳ਺ͷ࣮૷ํ๏ͷҧ͍ͷؒͰͷτϨʔυ ΦϑͰ͋ΔͱͱΒ͍͑ͯΔ w ίετ͕ɺͳʹʹ͔͔Δίετͳͷ͔ɺલड़ͨ͠ҙ ຯʹ͓͚Δlෛ࠴zͱlࢿຊzͷ۠ผ͕ͳ͍ͨΊɺ࣮ફ తؚҙ͕ബ͍ w
ϓϩδΣΫτͷεϙϯαʔ͕ɺ௚ۙͷίετʹ͔͠ ໨Λ޲͚ͳ͍ଘࡏͰ͋ΔͱܾΊ͔͔͍ͯͬͯΔ͕ɺ ίετʹର͢Δೝ͕ࣝҰ໘తͳ͍ͤͰͦ͏ͳ͍ͬͯ Δͱ͍͏ߟ͑ʹ͓ΑΜͰ͍ͳ͍

ෆ࣮֬ੑͱҙਤ w ະདྷͷෆ࣮֬ੑʹର͢Δʹɺ໌֬ͳҙਤΛ࣮࣋ͬͯ ૷ΛίϯτϩʔϧՄೳͱ͢Δߟ͑͸ɺརಘΑΓ΋ଛ ࣦͷํ͕େ͖͍ w lෛ࠴z͕͋ͬͨͱͯ͠ɺҙਤʹؼ੹ͯ͠΋ੜ࢈తͰ ͸ͳ͍ɻେࣄͳͷ͸ɺҙਤ͕Ͳ͏͋Εɺཱͪฦͬͯ ΍Γ௚ͤΔͱ͍͏͜ͱ $VOOJOHIBN
w զʑཱ͕͍ͬͯΔͷ͸͍ͭͰ΋ɺෆ࣮֬ͳະདྷͷલ Ͱ͋ͬͯɺ֬ఆͨ͠աڈʹ͍͔ͭͯ͋ͨ΋ਖ਼͍͠ҙ ਤ͕͋Γಘ͔ͨͷΑ͏ʹ;Γ͔͑ͬͨͱ͜ΖͰɺೝ ࣝརಘ͸ബ͍

ෆ࣮֬ੑͱҙਤ 0 55 110 165 220 2014 2015 2016 2017
2018 ݱ࣮త(੒௕཰10%) ཧ૝త(੒௕཰20%) ͔͜͜Β ݟΕ͹ ෆ࣮֬ੑˠ ͔͜͜Β ݟΕ͹ ˡҙਤత࣮૷

ٕज़తෆ࣮֬ੑͷྫ 0LV

μϝͳίʔυ͸ଐਓత͔ʁ w lٕज़తෛ࠴z͕΋͠ઓज़తɾઓུతτϨʔυΦϑ ͳͷͰ͋Ε͹ɺͻͱ͸ҙਤతʹʮμϝͳίʔυʯΛ ॻ͚Δ͜ͱʹͳΔͷͰ͸ͳ͍͔ w Ռͨͯͦ͠Ε͸ຊ౰͔ʁͦΜͳ͜ͱ͕ՄೳͳͷͩΖ ͏͔ʁ

ී௨ͷ'J[[#V[[

ҟৗͳ'J[[#V[[ 0TBXB

μϝͳίʔυ͸ଐਓత͔ʁ w ʮμϝͳίʔυʯΛҙࣝతʹॻ͘͜ͱ͸Ͱ͖ͳ͍ w ʮ͊͞ɺ͜Ε͔ΒμϝͳίʔυΛॻͧ͘ʂʯͱҙؾ ࠐΜͰॻ͖࢝ΊΔ͜ͱΛ૝૾͢ΔͱΑ͍ w ΫϦʔϯͳίʔυΛ஌Βͳ͍ͱɺҙࣝతʹμϝͳίʔ υΛॻ͘͜ͱ͸Ͱ͖ͳ͍ w
ͭ·Γʮμϝͳίʔυʯ͸ɺଐਓతͳ΋ͷͱ͍͏Α Γ΋Ή͠Ζɺ૊৫తɾࣾձతͳੜ੒෺Ͱ͋Δ

lෛ࠴zͱײ৘తίϯϑϦΫτ w lٕज़తෛ࠴z͸ɺײ৘తίϯϑϦΫτΛऒى͕͠ ͪɻͦͷͨΊϒϩάωλͱͯ͠සൟʹ׆༻͞ΕΔ w ίϯϑϦΫτͷݪҼ w աڈʹߦΘΕͨ੒Ռ෺Λlෛ࠴zͱΈͳ͢Έͳ͞ Εͨͱײ͡Δ w
ͦ͏ͨ͠lෛ࠴z͕ɺෆ౰ʹޡͬͨҙਤΛ࣋ͬͯߦ ΘΕͨͱΈͳ͢Έͳ͞Εͨͱײ͡Δ w ίϛϡχέʔγϣϯͷͨΊʹಋೖ͞ΕͨൺᄻͰ͋Δ ʹ΋ؔΘΒͣɺਖ਼͘͠༻͍ΒΕ͍ͯͳ͍

ιϑτ΢ΣΞ͸ࢿ࢈ 0LV

ࢿຊௐୡઓུ ιϑτ΢ΣΞ ࢿ࢈ ٕज़త lෛ࠴z ٕज़త lࢿຊz Ϣʔβ ະདྷ ݱࡏ

ࢿຊௐୡઓུ w ιϑτ΢ΣΞࢿ࢈Λܗ੒͢Δʹࡍͯ͠ɺظ଴͞ΕΔ ੒௕཰ͱݱ࣮తͳͦΕͱͷlΪϟοϓzΛຒΊΔͨ ΊʹඞཁͳࢿݯΛௐୡ͢Δඞཁ͕͋Δ w ͦͷࡍʹ՝୊ͱͳΔࣄ৅ʹԠͯ͡ɺௐୡ͞ΕΔࢿݯ Λlෛ࠴zͱlࢿຊzͱʹΘ͚ΒΕΔ w ͦ͏ͨ͠फ़ผΛߦΘͳ͍··ʹɺ໨ʹݟ͑Δlෛ࠴z
͹͔ΓʹͱΒΘΕΔͷ͸ɺޡͬͨઓུΛট͖ಘΔ

ٕज़తlෛ࠴z w ιϑτ΢ΣΞࢿ࢈Λܗ੒͢Δʹࡍͯ͠ௐୡ͞ΕΔݯ ઘͷ͏ͪɺͨͱ͑͹ҎԼͷΑ͏ͳ΋ͷ w ίʔσΟϯάن໿੔උͷอཹ w ςετΛ੔උ͢Δ͜ͱͷอཹ w υΩϡϝϯτΛ੔උ͢Δ͜ͱͷอཹ
w 04 ϥΠϒϥϦ౳ґଘίϯϙωϯτͷߋ৽อཹ w ڭҭମ੍Λ੔උ͢Δ͜ͱͷอཹ w ໨ʹݟ͑΍͍͢΋ͷ ,SVDIUFOFUBM w ൺֱతఆྔԽ͠΍͍͢

lෛ࠴zΛϚωδ͢Δ w όοΫϩάΛ ,SVDIUFOFUBM ʹै͍ɺ ৭෼͚ͯ͠؅ཧ͢Δ ػೳҎ֎ͷ΋ͷ΋؅ཧ͢Δ w
ςετ΍υΩϡϝϯτΛඞཁʹԠͯ͡੔උ͢Δɻͦ ͷঢ়گΛͰ͖Δ͚ͩՄࢹԽ͢Δ w ૊৫ͷ੒௕Λద੾ʹίʔυʹ൓ө͢Δ ϦϑΝΫλ Ϧϯά͢Δ w 04΍ϛυϧ΢ΣΞɺϥΠϒϥϦ΍ϑϨʔϜϫʔΫ Λৗʹ࠷৽ʹอͭ w ڭҭମ੍Λ੔උ͢Δ

ٕज़తlࢿຊz w ιϑτ΢ΣΞࢿ࢈Λܗ੒͢Δʹࡍͯ͠ௐୡ͞ΕΔݯ ઘͷ͏ͪɺͨͱ͑͹ҎԼͷΑ͏ͳ΋ͷ w Α͍ΞʔΩςΫνϟ w ಁ໌ੑͷߴ͍։ൃϓϩηε w ϝϯόͷϞνϕʔγϣϯ
w ϝϯόͷίϛοτϝϯτ w ֎෦͔Βͷ༏लͳਓࡐͷ࠾༻ w ໨ʹݟ͑ʹ͍͘΋ͷ ,SVDIUFOFUBM w ఆྔԽ͠ʹ͍͘

lࢿຊzௐୡίετΛϚωδ͢Δ w ະདྷͷෆ࣮֬ੑʹରԠՄೳͳΞʔΩςΫνϟʹɺద ੾ͳλΠϛϯάͰ࡞Γม͑Δ w ಁ໌ੑͷ͋Δ։ൃϓϩηεΛ࠾༻͢Δ w νʔϜϝϯόͷϞνϕʔγϣϯΛߴΊΔΑ͏ͳνϟ ϨϯδΛৗʹ͠ଓ͚Δ w
νʔϜϝϯόͷίϛοτϝϯτΛҾ͖ग़͢Α͏ͳ༏ Εͨιϑτ΢ΣΞΛ࡞Γଓ͚Δ w ૊৫֎෦ʹରͯ͠ɺັྗΛײͯ͡΋Β͑ΔΑ͏ͳٕ ज़޿ใΛߦ͏ ߦ͑ΔΑ͏ͳٕज़ମ੍Λ࡞Δ

૊৫తಉҰੑΛᔻཆ͢Δ w lෛ࠴zͷ$VOOJOHIBNతຊٛ͸ɺΑΓ੒௕ͨ͠ ະདྷʹ͓͍ͯɺ͍ͭͰ΋ͦΕΛίʔυʹ൓өͤ͞Β ΕΔͱ͍͏͜ͱ w ͔ͭͯະདྷͷෆ࣮֬ੑʹཱͪ޲͔ͬͨਚྗ͕ɺݱࡏ ʹ͓͍ͯlෛ࠴zʹݟ͑Δͱͨ͠ΒɺͦΕ͸૊৫ͱ͠ ͯͷ੒௕Λҙຯ͢Δ w
lෛ࠴zͱײ͡ΔࣗΒͷଘࡏ͕ɺ૊৫ʹͱͬͯͷ੒ ௕Ͱ͋ΔͱཧղͰ͖Δ͜ͱ͕૊৫తಉҰੑͷײಘͰ ͋Γɺίϛοτϝϯτʹͭͳ͕Δ

ίϛοτϝϯτ w ૊৫໨ඪͱݸਓ໨ඪͷҰக౓߹͍Λlίϛοτϝϯ τzͱ͍͏ ాඌ w ण໋ͷ௕͍ιϑτ΢ΣΞΛ։ൃ͢Δ૊৫ʹ͓͍ͯ͸ɺ อकɾվมίετ͕ߴ͍ιϑτ΢ΣΞ͕ɺաڈɾݱ
ࡏɾະདྷͷ૊৫తಉҰੑΛ્֐͠ಘΔ w աڈͷlෛ࠴zΛ%*4Δͱ͍͏ͷ͕యܕྫ w ૊৫తಉҰੑ͕ࠞཚ͍ͯ͠Δ૊৫ʹ͓͍ͯɺϝϯό ͷίϛοτϝϯτΛৢ੒͢Δͷ͸ࠔ೉

·ͱΊ w lٕज़తෛ࠴z͸ͨͱ͑࿩ʹա͗ͳ͍ɻ͔͠͠ɺ༗༻ ͳൺᄻͰ͋ΓಘΔ w ίϛϡχέʔγϣϯʹ໾ཱͭݶΓʹ͓͍ͯ༗༻ɻ%*4 Γ༻్͸ෆՄ w ࣗݾ΍νʔϜͷ੒௕Λɺ͍ͭͰ΋ίʔυʹཱͪฦͬ ͯ൓өͰ͖Δ
lෛ࠴zΛฦͤΔ ͱ͍͏ͷ͕ɺݴ͍ग़ ͬ͠΃Ͱ͋Δ$VOOJOHIBNతͳຊٛ w ະདྷͷෆ࣮֬ੑʹͲ͏ରॲ͢Δ͔͸ɺܦࡁֶ΍ϑΝ ΠφϯεͰ஝ੵͷ͋Δ෼໺ɻલ޲͖ʹଊ͑Ε͹ɺͦ ͷؚҙ͔Βଟ͘ͷ஌ݟΛಘΒΕΔ ͩΖ͏

ࢀߟจݙ • Conroy, P. (2012), “Technical Debt: Where Are the
Shareholders’ Interests?”, IEEE Software, November/December 2012 • Cunningham, W. (1992), “The WyCash Portfolio Management System”, http://c2.com/ doc/oopsla92.html • Cunningham, W. (2009), “Ward Explains Debt Metaphor”, http://c2.com/cgi/wiki? WardExplainsDebtMetaphor • Fowler, M. (2003), “TechnicalDebt”, http://www.martinfowler.com/bliki/ TechnicalDebt.html (֯੐య༁, “ٕज़తෛ࠴”, http://capsctrl.que.jp/kdmsnr/wiki/bliki/? TechnicalDebt) • Fowler, M. (2009), “TechnicalDebtQuadrant”, http://www.martinfowler.com/bliki/ TechnicalDebtQuadrant.html (֯੐య༁, “ٕज़తෛ࠴”, http://capsctrl.que.jp/kdmsnr/ wiki/bliki/?TechnicalDebtQuadrant) • Johann, S., Wolﬀ, E. (2013), “Managing Technical Debt”, http://www.infoq.com/articles/ managing-technical-debt (େా྘༁, “ٕज़తෛ࠴Λ؅ཧ͢Δ”, http://www.infoq.com/jp/ articles/managing-technical-debt) • Kruchten, P., Nord, R. L., Ozkaya, I. (2012), “Technical Debt: From Metaphor to Theory and Practice”, IEEE Software, November/December 2012

ࢀߟจݙ • ܀ྛ݈ଠ࿠ (2013)ʮͳͥʮܧଓతWebαʔϏεվળʯ͕ඞཁͳͷ͔ʙมԽʹରԠ͠ɼ10೥ ޙ΋ੜ͖࢒ΔWebαʔϏεͷͨΊʹʯʮWEB+DB PRESS Vol.75 ܧଓతWebαʔϏεվળ ΨΠυʯٕज़ධ࿦ࣾ •
McConnell, S. (2007), “Technical Debt”,http://www.construx.com/ 10x_Software_Development/Technical_Debt/ • Nord, R. L., Ozkaya, I., Kruchten, P., Gonzalez-Rojas, M. (2012), “In search of a metric for managing architectural technical debt” • Oku, K. (2013), Twitter΁ͷ౤ߘ, https://twitter.com/kazuho/status/415695299827359744 • Oku, K. (2014), Twitter΁ͷ౤ߘ, https://twitter.com/kazuho/status/436870682014515200 • Osawa, K. (2011), “Acme-FizzBuzz-0.03”, https://metacpan.org/release/YAPPO/Acme- FizzBuzz-0.03 • ੪౻ಯ (2006)ʮ࠶ੜࣄۀ͔Βݟͨ೔ຊʯhttp://jfn.josuikai.net/josuikai/21f/62/sai/sai.htm • Schmid, K. (2013), “Technical Debt — From Metaphor to Engineering Guidance: A Novel Approach based on Cost Estimation” • ాඌխ෉ (2012)ʰݱ୅૊৫࿦ʱႻ૲ॻ๪ • Wikipediaʮෛ࠴ʯhttp://ja.wikipedia.org/wiki/%E8%B2%A0%E5%82%B5

Rethinking Technical Debt

Rethinking Technical Debt

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