Vlume 2, Issue 1, Ocber 212 ISSN: 2277 128X Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg Research Paper Avalable le a: www.jarcsse.cm A Nvel Apprach Impleme Burdw Char SCRUM Mehdlgy Tazeem B Nr 1, Hasb B Shakur 2, Md Kharul Bashar Chwdhury 3, Imrul Muk Sddque 4 1,2 Lecurer, Dep. f Cmpuer Scece & Egeerg, Samfrd Uversy Bagladesh 3,4 Sfware Egeerg, NlavTechlges Ld. Absrac Sfware develpme mehdlgy s a pl f rules, heres, ad mehds ha prvde a paradgm fr plag, develpg ad maag sfware egeerg prjecs. The Agle mehdlgy s a sfware develpme mehdlgy ha prvdes erave ad cremeal slus wards buldg sfware s f varyg scales. Scrum s a ppularly pracced agle sfware develpme mehd he sfware dusry. I rder rack dw he prgress f a prjec a Bur Dw Char s used Scrum where remag asks are pled agas wrkg days ad he expeced ad acual prgress les are cmpared deerme he verall prgress f a prjec. Bu hs cmpars fe fals dcae he reass fr achevg he expeced gal eve wh axg effrs f he sfware develpme eam, as here s reflec f ay uplaed ask he Bur Dw Char. I hs paper, we have prpsed a mdfed vers f he rgal Bur Dw Char whch alg wh dsplayg he exsg expeced ad acual prgress le als dcaes wha exe uplaed asks have affeced he prgress f he prjec up her exsece. Keywrds Agle, Scrum, Spr, Spr Backlg, Bur Dw Char I. INTRODUCTION The Sfware Develpme prcess advaces hrugh a seres f seps. Fr successful cmple f sfware prjecs here arse several challeges hrughu he sfware develpme lfe cycle. User s requreme, desger s plag, adp f ew feaures ad develper s kwledge are eeded be egraed prperly he develpme f a sfware prjec. A umber f ls r mehdlges have bee evlved fr he successful delvery f sfware. Dffere sfware develpme appraches share cmm prcples such as mprveme f cusmer sasfac, maageme f chage requremes, delvery f wrkg sfware r sfware mdules, ad crea f cllabra amg sakehlders ad develpers [1]. Mehdlges efrce a well-rgazed prcess f sfware develpme wh a am f makg he sfware prjec mre predcable ad mre prfce by maag hgh qualy. Agle sfware develpme mehdlgy s a cllec f sfware develpme mehds based erave ad cremeal develpme [2] ha prmes adapably ad pe cllabra bewee self-rgazg, crss-fucal eams hrughu he lfe cycle f he prjec. Accrdg he Agle Mafes prcples [3], mre emphass s placed cusmer sasfac, erac wh he cusmer, wrkg sfware, cusmer cllabra, ad chage requremes, raher ha prcesses, ls, cracs ad plas. Scrum s e f he agle sfware develpme mehds whch are bradly used sfware develpme frms. Afer al plag, a seres f shr develpme phases, r Sprs, delver he prduc cremeally. A spr ypcally lass e fur weeks. A clsure phase usually cmplees prduc develpme. The eam racks all currely defed asks, capurg hem a ls called he Backlg. The backlg drves eam acvy. Befre each spr, he eam updaes he backlg ad reprrzes he asks each eam sgs up fr a umber f asks ad he execues a spr [4]. Geerally a spreadshee amed Bur Dw Char s used mr prjec prgress wh he curre wrk remag. Durg he spr hs char s daly updaed. I a bur-dw char, me prceeds alg he X-axs whereas he remag wrk s pled Y-axs. I deal scear le slpes dw wh me ad reaches zer a he ed f he spr. Sme agle mehdlgss prefer use Bur Up Char, a mdfca f Bur Dw Char. I a Bur Up Char he X-axs represes eras r me ad Y-axs dsplays accumulaed sry ps. Tal plaed wrk ad al prduced wrk are represeed by w dffere les [5].The remader f hs paper s srucured as fllws: The hsry f he Scrum mehd alg wh s prs ad cs s vervewed Sec II. Sec III descrbes he dealed mehdlgy f Scrum. Case Sudes have bee dscussed Sec IV. Sec V aalyzes he Bur Dw Chars f he case sudes. Alerave Bur Dw Char has bee prpsed Sec VI. Fally, Sec VII summarzes ad ccludes hs paper. II. SCRUM IN SOFTWARE DEVELOPMENT Scrum s a prcess used fr agle sfware develpme. Raher ha a full prcess r mehdlgy, s a agle framewrk fr effecve eam cllabra cmplex prjecs. I Scrum, a srucure s creaed by a small se f regulas fr eams s ha hey ca fcus her develpme effrs ad delver prducs f hghes pssble values. 212, IJARCSSE All Rghs Reserved Page 421
Tazeem e al., Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg 2 (1), Ocber- 212, pp. 421-427 Whe Jeff Suherlad appled he frs Scrum prcess 1993, he brrwed he erm "Scrum" frm a sudy f cmparable hgh-perfrmg, crss-fucal eams he Scrum frma used by Rugby eams descrbed by Takeuch ad Naka 1986 [6]. Afer a j presea Scrum mehdlgy by Suherlad ad Schwaber 1995[7], Schwaber wrked wh Mke Beedle descrbe he mehd he bk Agle Sfware Develpme wh Scrum 22[8]. Tday, Scrum s used by dffere cmpaes cludg: Yah!, Mcrsf, Ggle, Jhs Hpks APL, Semes, Csc, Mrla- SAP, Nka, GE, US Federal Reserve, Capal Oe [9]. The here prperes f Scrum have made hs mehdlgy wdely adped. The bjec reed apprach f he Scrum mehdlgy welcmes chagg requremes ad fcus prrzg dffere asks esure hghes qualy. Scrum esures eam spr hrugh beer cmmuca ad muual udersadg amg eam members. Teams are self-rgazed ad free develp deas ad slus ge he bes peal frmula rder cmplee he prjec prperly, ad as effcely as pssble. Overall, he lack f exeral plcy ad prcedure makes Scrum a useful ad uparalleled apprach prjec maageme ad effecve wrkflw [1]. Hwever, Scrum s a small eam mehdlgy wh c-lcaed ad fully cmmed eam. Iera plag eeds a l f experse ad daly Scrum meeg smemes ffers bsacles r verhead eam members as well as fr rgazas. Addally fdg a mea-scrum maser ad capable prduc wer are her challeges fr Scrum beg mplemeed accuraely ad apprpraely. III. DETAILED METHODOLOGY Scrum s a agle framewrk ha csss f Scrum Teams ad her asscaed rles, eves, arfacs, ad rules [11]. A. The Scrum Team A Prduc Ower, he Develpme Team, ad a Scrum Maser geher frm a self-rgazg ad crss-fucal Scrum Team. Ths eam fgures u he bes apprach carry u her asks dreced by he members f he eam whu depedg hers. 1) The Prduc Ower: Prduc wer s he prjec's key sakehlder wh cveys he vs f he prduc he eam by defg a prrzed feaure ls fr he prduc. The prduc wer s a pers raher ha a cmmee bu hwever he ca represe a cmmee. 2) The Develpme Team: A deal develpme eam csss f 3-8 prfessals empwered by rgaza wh d he wrk fr delvery f prducs wh sgfca creme. Geerally he eam cmprses wh prgrammers, QA (Qualy Assurace) prfessal ad aalyss. 3) The Scrum Maser: Scrum Maser s a serva-leader fr he Scrum Team ad wrks as a erface bewee he prduc wer, develpme eam ad rgaza. I s he respsbles f Scrum Maser esure ha Scrum s well udersd ad he pracce, rules f Scrum hery are adped prperly. B. Scrum Eves Fg.1 Scrum Mehdlgy [12] Scrum framewrk s maaed by Spr whch csss f Spr Plag Meeg, Daly Scrums, he develpme wrk, he Spr Revew, ad he Spr Rerspecve. 4) The Spr: Spr s a cfed wrk cycle r se perd f me durg whch peally releasable prduc creme s creaed. The spr lass fr 3 days r less. Befre hs me bx s ver, f spr gals becme bslee he he prduc wer ca cacel he spr. 212, IJARCSSE All Rghs Reserved Page 422
Tazeem e al., Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg 2 (1), Ocber- 212, pp. 421-427 5) Spr Plag Meeg: The cllabrave wrk f he ere Scrum Team deermes he spr gal f he Spr plag meeg. They agree he fucales ha wll be develped durg he spr ad als desg he sysem ad wrkflw acheve he fucales. 6) Daly Scrum: The daly Scrum meeg s a 15 mue eve ha held every day a he same me ad same place. The meeg revews he las day s ask saus ad explas wha wll be de fr ha day wh ask assgme dvdual members f he develpme eam. 7) Spr Revew: A he ed f he spr a spr revew meeg s held lk ver he verall prgress f he spr evaluaed by prduc wer. Ths s a frmal dem ha preses he feaures accmplshed durg he spr. 8) Spr Rerspecve: I a shr meeg f spr rerspecve, scpe f mprveme ad pprues are plaed by he develpme eam afer spr revew. C. Scrum Arfacs Three ypes f scrum arfacs represe he value r wrk esure success f scrum eam wh maxmum clary. 9) Prduc Backlg: The prduc backlg s a prrzed ls ha csss f all requremes ad feaures maaged by he prduc wer. I s fe rdered by mprace, rsk, values r prry. Smemes smalles u f prduc backlg s referred as a sry. 1) Spr Backlg: Frm prduc backlg, a se f ems s seleced perfrm fr he spr, s referred as spr backlg. Prduc requremes are brke maageable asks ad develpme eam wrks he asks make De fr he spr creme. Fg.2 Scrum Task bard [13] 11) Icreme: Prduc backlg ems cmpleed durg he spr dcae he creme. I hs sage, he feaures amed fr he spr mus be a usable cd ha refers De sae defed by he Scrum eam. 12) Bur Dw Char: T bserve he prgress f prjec develpme Bur Dw Char s used. I llusraes he remag wrk respec f me. The hrzal axs f Bur Dw Char dsplays me; he vercal axs shws he amu f wrk (sry p, wrk hur, eam days) remag. A spr Bur Dw Char exhbs daly prgress. The remag wrk shuld reduce a every day f a spr, s he deal scear fr spr Bur Dw Char wuld lk lke dwward sragh le as Fg. 3. Hwever, real me sme devas frm acual sragh le exs due wrg esma, prgrammer effcecy r add f ew requremes by he prduc wer. R e m a p g s r y 4 3 2 1 1 2 3 4 5 6 7 8 9 1 11 12 Spr Day Expeced Prgress Le Acual Prgress Le 212, IJARCSSE All Rghs Reserved Page 423
Tazeem e al., Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg 2 (1), Ocber- 212, pp. 421-427 Fg.3 Sample Bur Dw Char Fg.4 Ieras Scrum [14] O he her had, prduc s release Bur Dw Char demsraes mhly (per era r spr) prgress. Accrdg he release Bur Dw Char f Fg 4 s bserved ha wh plaed 11 eras, esma was chaged durg he 2 d era because f ew requremes ad sadard prgress was slwed dw durg he 7 h era. IV. CASE STUDIES A. Case Sudy 1 Prjec: Sck marke prfl maageme sysem f N Resde Ivesr Taka Amu (NITA) accu hlders f XYZ Bak Prjec Descrp: The am f hs prjec s prvde a sck marke prfl maageme sysem fr he NITA accu hlders f he XYZ bak. Users ca see her daly prfl updaed a he ed f each sck marke day; N. f avalable scks, value f he scks accrdg he laes marke prce ec. The sysem wll geerae dffere reprs regardg user s rasac daly/bweekly/ mhly/yearly. A mechasm s als avalable he sysem case f ay amaly user s rasacs where he sysem wll geerae a repr ad mal he respeced user abu he amaly. A reccla mechasm s als avalable he sysem reslve hs amaly. Prjec Dura: 8 weeks (2 mhs) Techlgy: Java 6., Eclpse Hels, Apache Axs 1., SOAP, JSP, Servle, XML, Srus 2., Sprg 2., Hberae, Apache Tmca 5.5 Web Caer, Mcrsf SQL Server 25 ec. Team Sze: 5 perss Team s Experece: 1 eam member s 5 years expereced ad he res are 1 year expereced Ma Days: (Team sze)*(n f weeks)*(n f wrkg days) = 5*8*5 = 2 Overvew: Agle Scrum mehdlgy was mplemeed hrughu he prjec. The al prjec was brke 4 w (2) week sprs (1 wrkg days per spr). The al desg, develpme ad esg phase f he sfware were dvded 4 majr mdules as gve belw. Requreme gaherg, aalyss, use case prepara ad daabase schema desg. Fle upladg, prcessg mdule ad relaed User Ierface (UI) mdule develpme ad esg. Prfl, malg, reccla ad relaed UI mdule develpme ad esg v. Repr geera mdule ad relaed UI mdule develpme ad esg Each spr was assumed cver (2/4) = sry ps ha s, 25 sry ps per week by he whle eam ad 1 sry p per pers each day. Frs w weeks f he prjec (1 s spr) were spe requreme gaherg ad requreme udersadg, prepara f use cases ad daabase schema fr he sysem. As a resul 2- = 1 ma days were avalable fr develpg ad esg he whle sysem befre he fal delvery. Afer he cmple f spr 2, 3 ad 4 ermedary releases were made. B. Case Sudy 2 Prjec: ABC Frum Prjec Descrp: The am f hs prjec s creae a le frum. Users wll regser le ad a adm wll apprve her regsra. Users wll be raked dffere classes based her crbu he frum. Users wll be able maage her w prfle, cusmze, creae a ew dscuss pc varus pcs (Ieracve pc crea), cmme pss hey are allwed cmme ad sed prvae mal her users ec. Prjec Dura: 12 weeks (3 mhs) R e m a g S r y P 6 4 3 2 1 1 2 3 4 5 6 7 8 9 1 11 12 13 Spr Day 6 4 3 2 1 1 2 3 4 5 6 7 8 9 1 11 12 13 Expeced Prgress Le Acual Prgress Le Expeced Prgress Le Acual Prgress Le Fg.5 Bur Dw Char f a Spr f Case Sudy 1 Fg.6 Bur Dw Char f a Spr f Case Sudy 2 Techlgy: Java 6., Eclpse Hels, Apache Axs 1., SOAP, JSP, Servle, XML, JFrum, Apache Tmca 5.5 Web Caer, AJAX, Freemarker, MySQL ec. Team Sze: 5 perss 212, IJARCSSE All Rghs Reserved Page 424
Tazeem e al., Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg 2 (1), Ocber- 212, pp. 421-427 Team s Experece: 1 eam member s 5 years expereced ad he res are begers wh her experece bewee 3 6 mhs. Ma Days: (Team sze)*(n f weeks)*(n f wrkg days) = 5*12*5 = 3 Overvew: Ths prjec als used agle Scrum mehdlgy bu hs me he sfware develpme eams experece s much less ha he sfware develpme eam f case sudy 1. The al prjec was dvded 6 w (2) weeks lg sprs. The sfware develpme ad esg phase was dvded 3 majr mdules:. Requreme cllec, aalyss, use case prepara, daabase schema desg. User Ierface desg, develpme ad esg. Operaal fucaly develpme ad esg Each spr was csdered cver (3/6) = sry ps, whch meas 1 sry p per pers each day. Afer each spr a ermedae release was made ad a dem presea was gve based he prgress f he prjec. V. ANALYSIS OF BURN DOWN CHART ON CASE STUDIES Bur Dw Char s a ppularly used l scrum rack dw he prgress f he prjec. I clearly dcaes he curre saus ad devas frm deal plag. I add, ca als acpae he las sadg f he prjec frm ay p f he char. Accrdg he Bur Dw Char f case sudy 1, hugh he arge f he spr was acheved a he ed bu he eam was uable keep pace wh acual plag he mddle f he spr. The eam was well eugh vercme he devas faced durg he spr. Hwever, case sudy 2, develpme eam faced sme prblems ad was uable acheve he arge f he spr. Tal sry p esmaed fr he spr was ad each member f he eam (5 perss) was assged cmplee 1 sry p a day. The prgress dgressed frm he 3 rd day f he spr ad he develpme eam was uable vercme durg he spr. S a he ed f he spr hey were uable cmplee 23 sry ps. The reass fr deva frm deal plag vary wh dffere eams dffere crcumsaces. We defy hree majr causes fr whch he acual le devaes frm deal scear. Frsly, accurae plag ca ae severe prblem spr Bur Dw Char. Ths ccurs whe he prduc wer smehw fals clearly cvey he prduc eeds he Scrum eam r he Scrum maser wrgly esmae he sry ps fr he develpme eam. Secdly, members f he develpme eam smemes fal cmplee he assged ask wh me perd due lack f experece ad adequae kwledge specfc asks. Fally, he chagg requremes f he cusmer hamper he regular prgress f he prjec whch resuls deva he Bur Dw Char. Whaever he reass behd he prblem are, sfware rgazas always eed defy hse specfcally s ha apprprae seps ca be ake mmedaely. VI. ALTERNATIVE BURN DOWN CHART (PROPOSED) A sadard Bur Dw Char llusraes he curre prgress f he prjec alg wh dffereces (f ay) frm acual esma. Hwever, des represe he acual reass fr deva. Fr example, he Bur Dw Char f case sudy 2, s udefed wheher he develpme eam faced ay uavdable crcumsaces r was uable accmplsh assged asks day 6. Oe f he slus prpsed vercme hs prblem s use Bur Up Chars [5]. Bur Up Char dsplays he amu f cmpleed sry ps each era alg wh he al esmaed ps fr he prjec. Mrever, s als ecessary kw he aswer wheher he eam was slw cmplee a specfc ask r sme ew asks were added he prjec. Oe slu f hs prblem ca be Phl Gdw ad Russ Rufer s Mdfed Bur Dw Char [5]. Ths s acually a bar graph where he hegh f each bar crrespds he remag sry ps. Addally, ew asks are shw a he bm f specfc bars. Here we are gg prpse aher frm f Bur Dw Char ha ca easly dsplay he add f ew asks alg wh he saus f he prjec. I hs char, a ew le has bee added ha represes he add f ew asks. The specfc spr day s represeed X-axs whereas ew asks are shw Y-axs erm f sry ps. R e m a g S r y P s 6 4 3 2 1 1 2 3 4 5 6 7 8 9 1 11 12 13 Spr Day Expeced Prgress Fg.7 Le Prpsed Bur Acual Dw Prgress Char Le Case Sudy Addal 2 Task Le The al p f hs le sads a (1, ) whch dcaes uplaed ask appeared he very frs day. New asks wh sry p 2 frs came u he 3 rd day f he prjec. Accrdg he spr ask bard f Table 1, he eam cmpleed 4 sry ps ha day bu ly 2 ps decreased frm remag sry p as he eam slved 212, IJARCSSE All Rghs Reserved Page 425
1 2 3 4 5 Tal De/ Plaed Upla ed Task Tazeem e al., Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg 2 (1), Ocber- 212, pp. 421-427 uplaed ask wh 2 sry ps. Smlarly, a he ed f day 6, acual remag sry p sayed uchaged a 42 due cmple f ew ask wh value 4. Sce spr day 3, ur prpsed ew le fr uplaed ask remaed sable a sry p 2 ul he spr day 5 whch mples add f uplaed ask durg hese days. Fally, he larges amu f ew ask (sry p f 6) added he prjec he 9h day f he spr whch s represeed by a seep rse uplaed ask le frm 6 sry ps 12 spr day 9. Eve hugh he eam cmpleed he hghes amu f asks (6 ps) ha day, he acual prgress le remaed sable due he accumula f he ew ask. O he her had, he sably f bh acual prgress le ad uplaed ask le he las day f spr clearly dcaes ha he eam cmpleed asks ha day. Ths prpsed graph meed Fg. 7 ca prvde a clear dea regardg he prgress f he prjec alg wh eam perfrmace. I add, he reas fr deva acual prgress le ca be easly defed by cmparg he acual prgress le wh he uplaed ask le. A he ed f he spr s clearly vsble frm he graph ha he spr resuled he ufshed ask f 23 sry ps f whch 12 were added as uplaed ask. Mrever, he graph als mples ha u f al 6 plaed sry ps, he eam was able cmplee (6-23) +12=49 sry ps whch jusfes he daa f able-1. TABLE I Day 1 1 1.25 1.75 4/5 2.75.25 2.5.5 4/5 3 1.75 1.5.75 4/5 2 4 1 1 1 3/5 5 1 1.25.75 1 1 5/5 6.25 1 1 1.75 4/5 4 7 1 1.25 1 1.75 5/5 8 1.25.75 1 1 4/5 9 1 1.75 1 1.5 1.75 6/5 6 1 1 1 1.5 1 4.5/5 11 1 1 1 1.5 1 5.5/5 12 /5 Tal 1 9.5 1.75 1.5 8.25 49/6 12 VII. CONCLUSIONS Scrum s a mmesely ppular agle mehdlgy amg sfware rgazas. A ypcal Bur Dw Char s uable clearly dcae he reass fr deva frm deal plag. I ur prpsed Bur Dw Char a addal uplaed ask le alg wh he expeced ad acual prgress le dcaes he reas fr dgressg frm he expeced prgress le. Frm hs prpsed graph, s pssble fd wheher eam s experece r add f uplaed asks resuls deva he acual prgress le. Hwever, hs Bur Dw Char sll des prvde her reass fr deva apar frm he add f ew ask. We wll ry upgrade hs char he fuure s ha mre reass fr devas ca be defed frm a Bur Dw Char. REFERENCES [1] Paesch, F., A. Eberle, ad F. Maurer, Requremes Egeerg ad Agle Sfware Develpme, Prceedgs f he Twelfh Ieraal Wrkshp Eablg Techlges: Ifrasrucure fr Cllabrave Eerprses, IEEE Cmpuer Scey, pp. 38, 23. [2] C. Larma ad V. Basl, Ierave ad Icremeal Develpme: A Bref Hsry, IEEE Cmpuer, vl. 36(6): 47-56, Jue 23. [3] (Sepember, 212) Prcples behd he Agle Mafes 21 [le]. Avalable : hp://aglemafes.rg/prcples.hml [4] Rsg, L.,Jaff, N.S., The Scrum sfware develpme prcess fr small eams, Sfware, IEEE, Vlume: 17, Issue: 4, pp. 26-32, Jul/Aug 2. [5] Md. Juad Arafee1, Saugaa Bse, Imprvg Sfware Develpme Usg Scrum Mdel by Aalyzg Up ad Dw Mvemes The Spr Bur Dw Char: Prps fr Beer Aleraves, Ieraal Jural f Dgal Ce Techlgy ad s Applcas Vlume 3, Number 3, pp. 19-115, Sepember 29. [6] (Sepember, 212) Why Is I Called Scrum? [le]. Avalable: hp://www.scrumallace.rg/pages/wha_s_scrum [7] Suherlad, Jeffrey Vcr; Schwaber, Ke, Scrum Mehdlgy, Busess bjec desg ad mplemea, OOPSLA '95 wrkshp prceedgs, The Uversy f Mchga. pp. 118, 1995. 212, IJARCSSE All Rghs Reserved Page 426
Tazeem e al., Ieraal Jural f Advaced Research Cmpuer Scece ad Sfware Egeerg 2 (1), Ocber- 212, pp. 421-427 [8] Schwaber Ke, Beedle Mke. Agle sfware develpme wh Scrum, 1s Ed, Prece Hall, 22. [9] (Sepember, 212) Jeff Suherlad s Scrum Hadbk [le]. Avalable: jeffsuherlad.cm/scrumhadbk.pdf [1] (Augus, 212) Scrum advaages [le]. Avalable: hp://www.scrummehdlgy.rg/scrum-advaages.hml [11] (Sepember, 212) The Scrum Gude-Develped ad susaed by Ke Schwaber ad Jeff Suherlad Ocber 211 [le]. Avalable: hp://www.scrum.rg/scrum-gudes [12] (Ocber, 212) Scrum Is a Ivave Apprach Geg Wrk De [le]. Avalable: hp://www.scrumallace.rg/lear_abu_scrum [13] (Ocber, 212) Trag fr Scrum Task Bard Use [le]. Avalable: hp://www.muagasfware.cm/scrum/ask-bards [14] (Ocber, 212) Release Bur Dw char [le]. Avalable: hp://www.muagasfware.cm/scrum/release-burdw 212, IJARCSSE All Rghs Reserved Page 427