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AANNAALLYYSSIISS Chapter 21Chapter 21

Implementation

Jerry PostCopyright © 1997

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Implementation ActivitiesImplementation Activities

Install hardware Install software Convert data Train operators Train users Implement security

procedures Evaluate process

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Hardwareadministration

Softwaredevelopment

Support end userdevelopment

Databaseadministration

Advocacy

Access tocorporate data

Software trainingand support

Corporatecomputingstandards

MIS RolesMIS Roles Hardware administration Software support Corporate data access Software development End user support Computing standards DB administration Advocacy

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Centralization v. DecentralizationCentralization v. Decentralization

Centralization DecentralizationHardware Share data

Share expensive hardwareControl purchasesControl usageLess duplicationEfficient use of resources

Less chance of breakdownUsers get personalized machinesMicrocomputers are cheaper

Software CompatibilityBulk buying discountsEasier trainingEase of maintenance

Different user preferencesEasier accessCustomization

Data Easy backupEasier to shareLess duplicationSecurity control & monitoring

Not all data needs to be sharedEasier & faster accessControl & politics

Personnel Similar worker backgroundsEasier trainingStraightforward career pathSpecialized staffEasier to see & control costs

Faster response to usersMore time with usersBetter understanding &communicationDifferent career path

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Conversion OptionsConversion Options

old

Direct cutover

Parallel

Pilot

Phased

dept or component 1dept or component 2dept or component 3dept or component 4

store 1store 2store 3store 4

New

New

old

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Distributed ComputingDistributed Computing

Data and code run on multiple computers in different locations.

Need a good network. Need really good DBMS. Two-tier.

Client: User Interface, forms Server: Database and code

Three-tier Server

Database Middle-ware

Business rules Code modules

Client User interface, forms

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Distributed ComputingDistributed Computing

Distributed Object Models CORBA: Common Object

Request Broker Architecture DCOM: Distributed

Computer Object Model, Active-X, (Microsoft)

Goals Location transparency. Scalability and expansion. Substitutability Modularity, replace rules or

DB, or front-end as needed.

Three-tier Forms and User Interface

interact with user on the client.

Events trigger code stored on a middle-ware server. Preferably following a standard distributed object model.

Code retrieves data from various servers as needed.

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Development Process EvaluationDevelopment Process Evaluation

Project evaluation Did the project meet

forecast times? Did it stay within budget? Did it meet user needs? Estimate size: e.g., function

point evaluation. Set up process for software

maintenance User input for changes. Programmer standards. Documentation

consolidation.

Future project lessons What would you do

differently next time? What steps worked better

than expected? Can development time and

costs be reduced?