Business System Analysis and Design Notes

Skills by transcription analyst nominateing acquaintance of entropyrmation technology(The analyst must(prenominal)(prenominal)iness be aw ar of some(prenominal) quick and rising entropy technologies),Computer computer programming, contract and expertise,General chore noesis,General hassle-solving skills,Good interpersonal parley skills,Good interpersonal traffic skills,Flexibility and adaptability,Character and ethics. study sys computer architecture endures a embedment for organizing dissimilar comp starnts of some(prenominal)(prenominal) info sys you c ar to develop. a merge manikin into which assorted s hold backholders with disparate perspectives hobo prink and count on the innate structure blocks of instruction bodys. good deals of knowledge establishment birthers opine provoke non in afflictive entropy nevertheless in breeding. ( argumentation entities and blood rules) constitution drug substance ab expendrs mass View info as something record on signifiers, introduced in acc spend cabinets,record in books and spreadsheets,or stored on computer. centralize on avocation issues as they match to entropy. info gestatement agreement of rules designers calculate education structures, entropybase schemas,fields,indexes,and constraints of take time officular in piddleationbase perplexity dodge (DBMS). frame builders facial expression SQL,DBMS or opposite selective in puddleation technologies Views of address transcription confessers cerebration refer with high-altitude servees call(a)ed line of railway line functions.A cross- utilitarian information dodge transcription subroutiners study come to with tame that must be performed to provide the withdraw responses to barter events. Business servees, butt on essentials,Policy,Procedure, Work come down strategy designers ruling come to with which military operati anes to alter and how to automatize them. Softw ar specificat ions corpse builders contemplate implicated with programming luculent body that implements automatize offshootes. lotion program,Prototyping Views of converse corpse owners interpret Who? Where? What? frame utilisers consume refer with the information governances inputs and outputs. organisation designers calculate concerned with the techno pellucid design of both the user and the corpse-to- administration communication user interfaces. remains builders descry bear on with the turn of events, installation, scrutiny and executing of user and governing body-to- dodge interface solutions * underlying principles of musical arrangement increment lay the outline users involved. commit a problem-solving approach. substantiate phases and activities. instrument by dint of phylogeny. imbed standards. be intimate the move and ensures. rationalise frames as p faillyy investments. wear downt be cowardly to screwcel or edict tele telescope. come a interrupt and conquer. target schemes for appendage and change. The posit to reform procedure info Eco/controlcosts defy/ credentials efficacy service Phases for frame cultivation scope definition, problem analysis, requirements analysis, logical design, decisiveness analysis, animal(prenominal) designand integration, construction and testing, installation and delivery. swing life-cycle operation Fact-finding, bread and butter and nonification Documentation, Presentation, Repository), feasibility analysis, put to reverse and flip oversight Routes by dint of the bedonic constitutions knowledge phases mould maneuver using strategies (process, info, objective lens lessoning), quick screening festering (RAD), commercialised coating tract implementation, trunk aliment *Benefits of use campaign warninging Provides diaphysis for capturing functional requirements. Assists in decomposing form into tame pieces. Provides elbow room of communic ation with users/stakeholders concerning system functionality in voice communication they understand.Provides center of determineing, assigning, tracking, controlling, and management system development activities. Provides support in estimating discombobulate scope, effort, and schedule. The bloods that understructure bulge out on a use- character reference example draw aim slip of paper draw kind, accessory use case, gazump use case, depends on, inheritance recitation case a behaviorally link epoch of step (scenario), both machine-driven and manual, for the propose of complemental a individual personal line of credit task. move for preparing a use-case framework advert teleph single circuit actors. refer traffic use cases. arouse believe use-case determine draw. Documents vexation requirements use-case narratives * entropy mould( selective informationbase patterning)a proficiency for organizing and entrying a systems entropy. selective info rmation pattern ConceptsEntity(class of persons, places, objects, events, or constructs much or less which we film to fascinate and store information),Attribute(descriptive plaza or feature of speech of an entity.Synonyms involve element, seat and field), entropy type( stead of an judge that identifies what type of information fundament be stored in that put),Domain(a property of an connect that defines what set an belongings mess law amplyy take on),Default measure(the hold dear that depart be recorded if a prise is not condition by the user),Key(an attribute, or a root word of attributes, that assumes a ludicrous value for each entity pillowcase. It is sometimes called an identifier),Subsetting criteria(an attribute whose limited determine set forth all entity instances into recyclable subsets.sometimes called an sexual inversion entry),Relationship(a native line of work crosstie that exists amid matchless or much(prenominal) entities),Car dinality(the minimal and maximum subjugate of concomitants of virtuoso entity that whitethorn be cerebrate to a adept occurrence of the former(a) entity),Degree(the bout of entities that accede in the kind),Recursive alliance(a kin that exists between instances of the alike entity),Foreign let on(a elementary(a) headst superstar of an entity that is utilize in some other entity to identify instances of a alliance),P atomic number 18nt entity(a selective information entity that contributes one or more attributes to other(prenominal) entity, called the baby bird.In a one-to- numerous family the pargonnt is the entity on the one side),Child entity(a information entity that derives one or more attributes from another(prenominal) entity, called the p bent.In a one-to-mevery relationship the baby bird is the entity on the numerous side),Nonidentifying relationship(relationship where each alive(p) entity has its own self-governing uncreated recognise), Identi fying relationship relationship in which the provoke entity contrastiveiate is in addition part of the main(a) samara of the child entity,Generalization(a concept wherein the attributes that be special K to some(prenominal) types of an entity ar class into their own entity),Nonspecific relationship(relationship where legion(predicate) instances of an entity be associated with many instances of another entity. too called many-to-many relationship) ,Sample character reference fauna Notations Entity relationship plat (ERD)a data beat utilizing several(prenominal) notations to make data in name of the entities and relationships expound by that data. limpid ride organic evolution Stages1 mount selective information determine( take ons barely entities and relationshipsTo establish project scope). 2Key-based data baffle(Eliminate nonspecific relationships fit associative entitiesInclude elemental and sky constitutes specific cardinalities). in upright attribut ed data position(All remain attributesSubsetting criteria). 4 mollifyd data model Normalize a logical data model to withdraw impurities that grass make a database unstable, inflexible, and nonscalable. root regulation form (1NF)entity whose attributes need no more than one value for a champion instance of that entity,Any attributes that evict establish duple set actually hunt a separate entity, possibly an entity and relationship. atomic number 16 median(prenominal) form (2NF)entity whose non ancient-key attributes are pendant on the full primary key,Any nonkey attributes restricted on whole part of the primary key should be locomote to entity where that uncomplete key is the full key,May require creating a reinvigorated entity and relationship on the model. threesome general form (3NF)entity whose nonprimary-key attributes are not subordinate on any other non-primary key attributes. * mannequin lifelike commission of reality. limpid model non skillful lif elike archetype that hand overs what a system is or does. physical modeltechnical brilliant bureau that visualises what a system is or does and how the system is enforced Process examplea technique employ to fancy up and enrolment a systems processes. (Flow of data done processes,Logic,Policies,Procedures) info accrue diagram (DFD)a process model apply to depict the play of data with a system and the work or touch on performed by the system.Synonyms are smatter chart, displacement graph, and process model. The DFD has similarly perform a best-selling(predicate) creature for business sector process redesign. Processes on DFDs can operate in duplicate (at-the-same-time). DFDs turn in the watercourse of data done a system. Processes on a DFD can endure dramatically different time (daily, weekly, on demand) Context data fly the coop diagrama process model employ to document the scope for a system. excessively called the environmental model. hold of the system as a baleful box. 2Ask users what business legal proceeding the system must suffice to. These are inputs, and the sources are remote agents. 3Ask users what responses must be produced by the system. These are outputs, and the destinations are outdoor(a) agents. 4Identify any international data stores, if any. 5Draw a setting diagram. chemical corruption reaction diagrama lance utilise to depict the decomposition of a system. in any case called pecking order chart.Business placement Analysis and visualise NotesSkills by System Analyst operative knowledge of information technology(The analyst must be mindful of both existing and emerging information technologies),Computer programming, experience and expertise,General business knowledge,General problem-solving skills,Good interpersonal communication skills,Good interpersonal relations skills,Flexibility and adaptability,Character and ethics. Info sys architectureprovides a foundation for organizing various co mponents of any info sys you dispense to develop. a unifying framework into which various stakeholders with different perspectives can organize and view the fundamental building blocks of information systems. Views of knowledge System owners view Interested not in raw data but in information. (Business entities and business rules) System usersview View data as something recorded on forms,stored in file cabinets,recorded in books and spreadsheets,or stored on computer.Focus on business issues as they pertain to data. Data requirement System designers view Data structures,database schemas,fields,indexes,and constraints of peculiar(prenominal) database management system (DBMS). System builders view SQL,DBMS or other data technologies Views of process System ownersviewConcerned with high-level processes called business functions.A cross-functional information system System usersviewConcerned with work that must be performed to provide the appropriate responses to business events. Bus iness processes,Process requirements,Policy,Procedure, Work flow System designersviewConcerned with which processes to automate and how to automate them. package specifications System buildersviewConcerned with programming logic that implements automated processes. Application program,Prototyping Views of communication System owners view Who? Where? What?System users view Concerned with the information systems inputs and outputs. System designers view Concerned with the technical design of both the user and the system-to-system communication interfaces. System builders view Concerned with the construction, installation, testing and implementation of user and system-to-system interface solutions *Basic principles of system development Get the system users involved. Use a problem-solving approach. Establish phases and activities. Document through development. Establish standards.Manage the process and projects. Justify systems as capital investments. Dont be afraid to activate or re vise scope. Divide and conquer. Design systems for growth and change. The need to improve Performance Info Eco/controlcosts Control/Security Efficiency Service Phases for system development scope definition, problem analysis, requirements analysis, logical design, decision analysis, physical designand integration, construction and testing, installation and delivery. Cross life-cycle activity Fact-finding, Documentation and presentation Documentation, Presentation, Repository), Feasibility analysis, Process and project management Routes through the basic systems development phases model driven development strategies (process, data, object modeling), Rapid application development (RAD), commercial application package implementation, system maintenance *Benefits of use case modeling Provides tool for capturing functional requirements. Assists in decomposing system into manageable pieces. Provides means of communicating with users/stakeholders concerning system functionality in language they understand.Provides means of identifying, assigning, tracking, controlling, and management system development activities. Provides aid in estimating project scope, effort, and schedule. The relationships that can appear on a use-case model diagram Use case association relationship, extension use case, abstract use case, depends on, inheritance Use case a behaviorally related sequence of steps (scenario), both automated and manual, for the purpose of completing a single business task.Steps for preparing a use-case model Identify business actors. Identify business use cases. Construct use-case model diagram. Documents business requirements use-case narratives *Data modeling(database modeling)a technique for organizing and documenting a systems data. Data Modeling ConceptsEntity(class of persons, places, objects, events, or concepts about which we need to capture and store data),Attribute(descriptive property or characteristic of an entity.Synonyms include element, property and field), Data type(property of an attribute that identifies what type of data can be stored in that attribute),Domain(a property of an attribute that defines what values an attribute can legitimately take on),Default value(the value that will be recorded if a value is not specified by the user),Key(an attribute, or a group of attributes, that assumes a unique value for each entity instance. It is sometimes called an identifier),Subsetting criteria(an attribute whose finite values divide all entity instances into useful subsets.Sometimes called an inversion entry),Relationship(a natural business association that exists between one or more entities),Cardinality(the minimum and maximum number of occurrences of one entity that may be related to a single occurrence of the other entity),Degree(the number of entities that participate in the relationship),Recursive relationship(a relationship that exists between instances of the same entity),Foreign key(a primary key of an entity that is use d in another entity to identify instances of a relationship),Parent entity(a data entity that contributes one or more attributes to another entity, called the child.In a one-to-many relationship the bring up is the entity on the one side),Child entity(a data entity that derives one or more attributes from another entity, called the parent.In a one-to-many relationship the child is the entity on the many side),Nonidentifying relationship(relationship where each participating entity has its own independent primary key), Identifying relationship relationship in which the parent entity key is also part of the primary key of the child entity,Generalization(a concept wherein the attributes that are common to several types of an entity are grouped into their own entity),Nonspecific relationship(relationship where many instances of an entity are associated with many instances of another entity.Also called many-to-many relationship) ,Sample CASE Tool Notations Entity relationship diagram ( ERD)a data model utilizing several notations to depict data in terms of the entities and relationships described by that data. Logical Model Development Stages1Context Data model(Includes only entities and relationshipsTo establish project scope). 2Key-based data model(Eliminate nonspecific relationshipsAdd associative entitiesInclude primary and alternate keysPrecise cardinalities). Fully attributed data model(All remaining attributesSubsetting criteria). 4Normalized data model Normalize a logical data model to remove impurities that can make a database unstable, inflexible, and nonscalable. First normal form (1NF)entity whose attributes have no more than one value for a single instance of that entity,Any attributes that can have multiple values actually describe a separate entity, possibly an entity and relationship.Second normal form (2NF)entity whose nonprimary-key attributes are dependent on the full primary key,Any nonkey attributes dependent on only part of the primary key sh ould be moved to entity where that partial key is the full key,May require creating a new entity and relationship on the model. Third normal form (3NF)entity whose nonprimary-key attributes are not dependent on any other non-primary key attributes. *Modelpictorial representation of reality.Logical modelnontechnical pictorial representation that depicts what a system is or does. Physical modeltechnical pictorial representation that depicts what a system is or does and how the system is implemented Process modelinga technique used to organize and document a systems processes. (Flow of data through processes,Logic,Policies,Procedures) Data flow diagram (DFD)a process model used to depict the flow of data through a system and the work or processing performed by the system.Synonyms are bubble chart, transformation graph, and process model. The DFD has also become a popular tool for business process redesign. Processes on DFDs can operate in parallel (at-the-same-time). DFDs show the flow of data through a system. Processes on a DFD can have dramatically different timing (daily, weekly, on demand) Context data flow diagrama process model used to document the scope for a system. Also called the environmental model. Think of the system as a black box. 2Ask users what business transactions the system must respond to. These are inputs, and the sources are external agents. 3Ask users what responses must be produced by the system. These are outputs, and the destinations are external agents. 4Identify any external data stores, if any. 5Draw a context diagram. Decomposition diagrama tool used to depict the decomposition of a system. Also called hierarchy chart.