Slide INF205 RPL Pertemuan 2

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REKAYASA PERANGKAT

LUNAK

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Pendahuluan

• Software project management

begins

with a set of activities

that are called

project planning.

• Before the project can begin, the manager and the software

team must estimate the

work

to be done, the

resources

that

will be required, and the

time

that will elapse from start to

finish.

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Pendahuluan

• Estimation begins with a description of

the scope

of the

product.

• The problem is then

decomposed

into a set of smaller

problems and each of these is

estimated

using historical

data and experience as guides.

• _{It is advisable to generate your estimates using at least two}

different methods

(as a cross check).

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Tujuan Perencanaan PPL

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Scope (Ruang Lingkup) PL

• The

first activity

in software project planning is the

determination of software scope.

• Unambiguous

and

understandable

at the management and

technical levels.

• A statement of software scope must be

bounded

.

• _{Software scope}

_describes

_{the data and control to be}

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Mendapatkan Ruang Lingkup

• _{Conduct a preliminary meeting or interview.}

• _{Example questions:}

• _{Who is behind the request for this work?} • _{Who will use the solution?}

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Feasibility (Kelayakan)

• Scoping is not enough.

• “Can we build software to meet this scope?

Is the project

feasible?”

• Four solid dimensions:

• _{Technology —}Is it within the state of the art?

• _{Finance —}Can development be completed at a cost the software organization, its client, or the market can afford?

• _{Time —}Will the project’s time-to-market beat the competition?

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Perspektif Sumber Daya

• _{Masing-masing sumber daya tersebut dispesifikasikan}

dengan 4 karakteristik berikut ini:

• _{Deskripsi  Siapa, Apa}

• _{Ketersediaan  Jumlah dan kualitas} • _{Waktu  Kapan digunakan}

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SOFTWARE PROJECT ESTIMATION

• To achieve reliable cost and effort estimates, a number of

options arise:

a) Delay estimation until late in the project (obviously, we can achieve 100% accurate estimates after the project is complete!).

b) Base estimates on similar projects that have already been completed.

c) Use relatively simple decomposition techniques to generate project cost and effort estimates.

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Teknik Dekomposisi

• _{Software sizing}

• _{Problem based estimation}

• _{LOC based estimation}

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COCOMO Model

• _{COnstructive COst MOdel.} • _{Address the following areas:}

• _{Application composition model}_{. Used during the early stages} of software engineering, when prototyping of user interfaces,

consideration of software and system interaction, assessment of performance, and evaluation of technology maturity.

• _{Early design stage model.}_{Used once requirements have been} stabilized and basic software architecture has been established. • _{Post-architecture-stage model}_{. Used during the construction}

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Keputusan: Beli atau Buat?

• Software engineering managers are faced with a

make/ buy

decision

:

• (1) software may be purchased (or licensed) off-the-shelf,

• (2) “full-experience” or “partial-experience” software

components may be acquired and then modified and

integrated to meet specific needs, or

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Outsourcing

• _{Software engineering activities are contracted to a third party} who does the work at lower cost and, hopefully, higher quality. • _{Software work conducted within a company is reduced to a}

contract management activity.

• _{The decision to outsource can be either strategic or tactical.}

• _{(+) Cost savings can usually be achieved by reducing the number} of software people and the facilities (e.g., computers, network). • _{(-) A company loses some control over the software that it needs.}

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Six Generic Functions

• _{1. Sizing of project deliverables}_{. Work products include the external}

representation of software (e.g., screen, reports), the software itself (e.g., KLOC), functionality delivered (e.g., function points), descriptive information (e.g. documents).

• _{2. Selecting project activities.}_{The appropriate process framework is}

selected and the software engineering task set is specified.

• _{3. Predicting staffing levels.}_{The number of people who will be available to}

do the work is specified.

• _{4. Predicting software effort.}_{Estimation tools use one or more models}

(e.g., Section 5.7) that relate the size of the project deliverables to the effort required to produce them.

• _{5. Predicting software cost.}_{Given the results of step 4, costs can be}

computed by allocating labor rates to the project activities noted in step 2.

• _{6. Predicting software schedules.}_{When effort, staffing level, and project}

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Kesimpulan

• _{The software project planner must estimate three things}

before a project begins:

• _{How long it will take,}

• _{How much effort will be required, and} • _{How many people will be involved.}

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Kesimpulan

• _{Decomposition techniques require a delineation of}

major software functions, followed by estimates of

either

• _{(1) the number of LOC,}

• _{(2) selected values within the information domain,}

• _{(3) the number of person-months required to implement each} function, or