SYSTEMSDESIGNANALYSIS 1 Chapter 21 Implementation Jerry Post Copyright © 1997

SYSTEMSDESIGN 2 Implementation Activities  Install hardware  Install software  Convert data  Train operators  Train users  Implement security procedures  Evaluate process

SYSTEMSDESIGN 3 Hardware administration Software development Support end user development Database administration Advocacy Access to corporate data Software training and support Corporate computing standards MIS Roles  Hardware administration  Software support  Corporate data access  Software development  End user support  Computing standards  DB administration  Advocacy

SYSTEMSDESIGN 4 Centralization v. Decentralization

SYSTEMSDESIGN 5 Conversion Options old Direct cutover Parallel Pilot Phased dept or component 1 dept or component 2 dept or component 3 dept or component 4 store 1 store 2 store 3 store 4 New old

SYSTEMSDESIGN 6 Distributed 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

SYSTEMSDESIGN 7 Distributed 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.

SYSTEMSDESIGN 8 Development 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?