Requirements Engineering Sesion 2

7/31/2019 Requirements Engineering Sesion 2

1/23

1

Maest r a en Gest in de Tecnologas de laI nformacin y Comunicacin

Curso: I ngeniera de requerimient os(Requirement Engineering)

Febrero-Marzo 2010

Sesin 2 (4/ 02/ 2010)

[email protected]


2/23

LPP 2

Requerimientos como una red deelementos vinculadosdetalles!

Requerimientos

Razones(Rationale)

Interfaces

Prioridades

Metas

Stakeholder

Escenarios

Mediciones

Funcionales No-funcionales Restricciones

Tienen subtipos

Definen un trmino en

Verifican

Ocurren en

Tienen un rol en

Es propiedad de

Satisfacen

Tienen importancia

Conectan con

Son justificados por

Definiciones


3/23

LPP 3

Stakeholders Quin tiene un vlido inters en el producto/servicio?

Cmo involucramos y manejamos el contacto conestas personas?

Que requerimiento viene de cul stakeholder?

-----------------------------------------------------------------

Son ms que los desarrolladores o usuarios. Piensenen beneficiarios, operadores, involucrados indirectos,involucrados negativos, reguladores, etc.


4/23

LPP 4

Metas

Qu trata de conseguir/hacer? Para qu es esto?

-------------------------------------------------------

Pueden ser metas que no son totalmente

alcanzables (visin), pueden ser difusas (sinmediciones), pueden se conflictivas (nocundo se expresan en los requerimientos).

Se mejoran y refinan eventualmente!!!


5/23

LPP 5

Mediciones Cmo se sabr que este requerimiento se ha logrado

satisfactoriamente? Cmo puedes medir la entrega de este

requerimiento?

Cmo sabremos que el producto/sistema hace lo quedice que hace? Cmo sabremos que los suplidores han hecho lo que

han dicho que harn?

------------------------------------------------- La experiencia indica que cundo no se puede

contestar algunas de estas preguntasquizs hayrequerimientos ms simples (medibles) que estnincludos en el que se est analizando


6/23LPP 6

Interfaces (contexto y foco)

Qu debe ser includo, y qu debe ser dejado fueradel producto/servicio?

Donde est la frontera del producto/servicio?

Qu estrategias necesito para definir el foco delproducto/servicio?

-------------------------------------------

No es fcil! Se necesita de iteraciones y refinamiento.

Se inicia dnde se tenga informacin!!!


7/23LPP 11

Caractersticas de un buenrequerimiento

Characteristic Explanation

Unitary

(Cohesive)The requirement addresses one and only one thing.

Complete The requirement is fully stated in one place with no missing information.

ConsistentThe requirement does not contradict any other requirement and is fully consistent with

all authoritative external documentation.

Non-Conjugated

(Atomic)

The requirement is atomic, i.e., it does not contain conjunctions. E.g., "The postal code

field must validate American andCanadian postal codes" should be written as two

separate requirements: (1) "The postal code field must validate American postal codes"and (2) "The postal code field must validate Canadian postal codes".

TraceableThe requirement meets all or part of a business need as stated by stakeholders and

authoritatively documented.

Current The requirement has not been made obsolete by the passage of time.


8/23LPP 12

Caractersticas de un buenrequerimiento

Feasible The requirement can be implemented within the constraints of the project.

Unambiguous

The requirement is concisely stated without recourse to technical jargon, acronyms

(unless defined elsewhere in the Requirements document), or other esoteric

verbiage. It expresses objective facts, not subjective opinions. It is subject to one

and only one interpretation. Vague subjects, adjectives, prepositions, verbs and

subjective phrases are avoided. Negative statements and compound statements

are prohibited.

Mandatory

The requirement represents a stakeholder-defined characteristic the absence of

which will result in a deficiency that cannot be ameliorated. An optional requirementis a contradiction in terms.

VerifiableThe implementation of the requirement can be determined through one of four

possible methods: inspection, demonstration, test or analysis.


9/23LPP 13

Una herramienta para definirrequerimientos


10/23LPP 14

Ejemplos de requerimientos The SATURN system shall be available for use by all

HR representatives at each company facility(Product ion process requirement > ?)

The SATURN system shall be developed to providecompany-wide access to employee skills and traininginformation to all HR representatives(Process Funct ional Requirement > ?)

Managers need access to timely and accurate data onpersonnel in order to meet operational needs.(Business Requirements > ?)


11/23LPP 15

Ejemplos de requerimientos The SATURN system shall complete all retrievals and

display the requested information, within one minuteof the user entering the query (Performance > ?)

The SATURN system shall return all available skill-sets to the user within one minute of initiating asearch (Performance Requirements > ?)

Up to 20 concurrent users may use the SATURNsystem without any degradation of response time(Performance > ?)


12/23LPP 16

Ejemplos de requerimientos

The SATURN system shall retrieve basicidentifying information for all employeesmeeting the specified criteria(Funct ional Requirement > ?)

The SATURN system shall retrieve basic

identifying information for all employees whomeet the pre-determined skills and trainingcriteria(Product Requirement > ?)


13/23LPP 17

Ejemplos de requerimientos Data formats shall be translated across legacy system boundaries into

the format supported by the local users system(Product Requirement s > ?)

The SATURN system will have the same look and feel at each companylocation that users of the system at that location are familiar with, andtherefore shall require no training(Operat ional Process Requirement > ?)

The SATURN systems look and feel shall be identical to each locallegacy system (Product I nt erface Requirement > ?)

There shall be no operational impact to any user other than the impacton information retrieval caused by larger population of employees fromwhich to select (Environmental Requirements > ?)


14/23LPP 18

Ejemplos de requerimientos The SATURN system shall retrieve basic identifying information

for all employees meeting the specified criteria(Funct ional Requirement > ?)

The SATURN system shall retrieve basic identifying information

for all employees who meet the pre-determined skills andtraining criteria(Product Requirement > ?)

Skills and training information from all company locations will be

available to all other company locations(Process I nt erface Requirement > ?)

To ensure complete skills and training information are captured

among the legacy systems, a data model shall be created(Process Specialt y Requirement > ?)


15/23LPP 19

Ejemplos de requerimientos The HR user shall be able to retrieve employee skills and

training data by predefined categories(Product Funct ional Requirement > ?)

The user needs the capability to search on personnel across the

entire company by pre-defined skill sets(User Requirements > ?)

The local user shall be able to search all legacy systems in apredefined local, regional, or national geographical area for

personnel meeting a specified skill-set(Funct ional Requirements > ?)


16/23LPP 20


The SATURN system shall operate through acommercially available browser such asInternet Explorer or Mozilla( I nterface Requirement > ?)

The SATURN system shall run on commercial

off the shelf (COTS) hardware using theMicrosoft Windows Operating System(Specialt y Engineering Requirement > ?)


17/23LPP 21


The SATURN system shall operate onsingle phase commercially availablepower with a line voltage in the range

of 110 volts plus or minus 20 volts AC(Environmental Requirement > ?)


18/23LPP 22

Ejemplos de requerimientos Test HR records for verifying the SATURN

system will consist of a special set ofpersonnel records at each company locationspecifically created with artificial data

(Test Process Requirement > ?)

The SATURN system will generate error

messages when a query fails to run tocompletion or a legacy system is notresponding within the allotted time(Non-Funct ional Requirement > ??)


19/23LPP 23

Ejemplos de requerimientos The SATURN system shall maintain cross- references

for information types contained in the legacysystems. For example the field called

education_level in one system is the same as

education in another(High-Level ( or System Level) Requirements > ?)

The SATURN system shall convert data from each

legacy system to the data expected by the local user.For example a masters degree in one system mightbe reflected in another system as Grade 17.(High-Level ( or System Level) Requirements > ?)


20/23LPP 24


SATURN shall be developed using JointApplication Development teams (JAD)composed of users (HR representatives),

developers, and system testers(Process Environment al Requirement > ?)

The SATURN system shall use relationaldatabase technology(Product Specialt y Requirement > ?)


21/23LPP 25


The SATURN system shall be ready forsystem acceptance testing within 180 days ofproject inception

(Process Performance Requirement > ?)

The SATURN system shall operate with 97%reliability, 24 hours a day, 7 days a week(Product Performance Requirement > ?)


22/23LPP 26


The SATURN system shall make use of thepublic switched network (PSN) and notrequire dedicated lines of communication(Funct ional Requirement sNon-funct ional Requirement s > ?)

The SATURN system shall use Public KeyInfrastructure (PKI) communications security(Der ived (or Design) Requirement s and

Design Const raints > ?)


23/23

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Gracias por su atencin, a los que no sedurmieron!

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Requirements Engineering Sesion 2

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