Lecture.01b.edited

7/25/2019 Lecture.01b.edited

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The Origins ofSoftware

2008 by Prentice Hall


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Learning Objectives

Explain outsourcing.

Describe six different sources of software.

Discuss how to evaluate offtheshelfsoftware.

Explain reuse and its role in software

develop!ent.


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System Acquisition: Outsourcing

"urning over responsibility of so!e or all of anorgani#ation$s infor!ation syste!s applications andoperations to an outside fir!

%easons to outsource &osteffective "a'e advantage of econo!ies of scale (ree up internal resources %educe ti!e to !ar'et )ncrease process efficiencies *yste! develop!ent is a noncore activity for the

organi#ation


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Systems Acquisition: Outsourcing

+utsourcing Exa!ples, co!pany that runs payroll applications

for clients., co!pany that runs your applications at

your site.


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Various Levels of Outsourcing


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2008 by Prentice Hall 6&hapter 2

Information Technology (IT

Services !irms Help co!panies develop custo! infor!ation

syste!s for internal use.

Develop- host- and run applications forcusto!ers.

Provide other services.


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"ac#age$ Software

"ro$ucers *erve !any !ar'et seg!ents. *oftware ranges fro! broadbased

pac'ages i.e. general ledger/ toniche pac'ages i.e. day care!anage!ent/.


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"ac#age$ Software

"ro$ucers *oftware runs on !icroco!puters to

large !ainfra!es. Prepac'aged software is offtheshelf

software.


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"ac#age$ Software "ro$ucers

(%ont& Prepac'aged software is turn'ey

software i.e. not custo!i#able/. +fftheshelf software at best !eets

0 percent of organi#ation1s needs.


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"re'ac#age$ Software

(igure 22 icrosoft Pro3ect


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nter'rise Solutions

Software Enterprise Resource Planning (ERP) syste!s

that integrate individual traditional business

functions into !odules enabling a singlesea!less transaction to cut across functionalboundaries.

*,P ,4 is the leading vendor of E%P syste!s.


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nter'rise Solutions Software

(%ont&

(igure 25 (unctional areas supported by +racle1s 6usiness *uitefor s!all to !ediu! businesses


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A''lication Service "rovi$er

(AS",n organi#ation that re!otely

hosts and runs co!puterapplications for other co!panies-typically on a peruse or licensebasis.


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A''lication Service "rovi$er

(AS" (%ont&,pplication service providers ,*Ps/

buy- install- !aintain- and upgrade the

applications.,pplication service providers ,*Ps/

purchase or license applications fro!

other software vendors.


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)anage$ Service "rovi$er

()S",n organi#ation that re!otely

provides custo!i#ed co!puter

applications and networ'basedservices for other co!panies for a!onthly or peruse fee.


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)anage$ Service "rovi$er

()S" (%ont& *Ps provide the ability to gain

access to large and co!plex syste!s

without the expense and ti!econsu!ing i!ple!entation.


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O'en Source Software

(reely available including source code. Developed by a co!!unity of interested

people. Perfor!s the sa!e functions as co!!ercial

software.

Exa!ples7 inux- !y*9- (irefox.


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In*+ouse ,evelo'ment

)f sufficient syste! develop!ent expertise withthe chosen platfor! exists inhouse- then so!e

or all of the syste! can be developed by theorgani#ation1s own staff. Hybrid solutions involving so!e purchased and

so!e inhouse co!ponents are co!!on.


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O-*the*Shelf Software

ost co!!on criteria for selecting7 Cost7 co!paring the cost of

developing the sa!e syste! inhousewith the cost of purchasing orlicensing the software pac'age.


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Functionality7 the tas's that thesoftware can perfor! and the

!andatory- essential- and desiredsyste! features.


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(%ont&Vendor support7 whether or how

!uch support the vendor canprovide and at what cost.


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(%ont&Viability of vendor7 can the

software adapt to changes insyste!s software and hardware.


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(%ont& Flexibility7 how easy it is to

custo!i#e the software. Documentation7 is the user1s !anual

and technical docu!entationunderstandable and uptodate.


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(%ont& Response time7 how long it ta'es the

software pac'age to respond to the

user1s re:uests in an interactivesession.

Ease of installation7 a !easure of

the difficulty of loading the softwareand !a'ing it operational.


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Vali$ating "urchase$ Software

Information ;se a variety of infor!ation sources7 &ollect infor!ation fro! vendor.

*oftware docu!entation. "echnical !ar'eting literature.


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.equest !or "ro'osal (.!"

Request for proposal RFP/ is adocu!ent provided to vendors to as'

the! to propose hardware andsyste! software that will !eet there:uire!ents of a new syste!.


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.equest !or "ro'osal (.!"

(%ont& *o!eti!es called a Request For

QuoteRFQ/. 6ased on vendor bids- analyst selects

best candidates. ;se a variety of infor!ation sources.


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Information Sources !or .!"


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.euse

"he use of previously written softwareresources- especially ob3ects and

co!ponents- in new applications. &o!!only applied to two different

develop!ent technologies7 +b3ectoriented develop!ent &o!ponentbased develop!ent


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.euse (%ont&

Objectoriented development +b3ect class encapsulates data and behavior of

co!!on organi#ational entities e.g. e!ployees/ Componentbased development

&o!ponents can be as s!all as ob3ects or aslarge as pieces of software that handle single

business functions.


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.euse (%ont&

+b3ectoriented develop!entreuse is using ob3ect classes in!ore than one application e.g.E!ployee/.


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.euse (%ont&

&o!ponentbased develop!entreuse is the asse!bly of anapplication fro! !any differentco!ponents at !any differentlevels of co!plexity and si#e e.g.&urrency conversion/.


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%osts an$ /ene0ts of .euse


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A''roaches to .euse

!d"oc7 individuals are free to find ordevelop reusable assets on their own.

Facilitated7 developers are encouraged topractice reuse.


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A''roaches to .euse (%ont&

#ana$ed7 the develop!ent- sharing- andadoption of reusable assets is !andated.

Desi$ned7 !andating assets be designed forreuse as they are being designed for specificapplications.


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2008 b P ti H ll 39

Summary

)n this chapter you learned how to7Explain outsourcing.

Describe six different sources of software.

Discuss how to evaluate offtheshelf software.

Explain reuse and its role in softwaredevelop!ent.

Lecture.01b.edited

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