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This plan outlines the needs, relationships, and modeling of major subjects, keys, and attributes in migration to an architected environment. It addresses the impact analysis, resources estimate, and a data-driven development methodology for successful migration.
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Migration Plan • Corporate data model • Needs to identify the following • Major subjects of the corporation • Definition of the major subjects of the corporation • Relationships between the major subjects • Grouping of keys and attributes that more fully represent the major subjects, including the following : • Attributes of the major subjects • Keys of the major subjects • Repeating groups of keys and attributes • Connectors between major subject areas • Subtyping relationships • Example
The Feedback Loop Data Warehouse Existing systems environment DSS Analyst Data Architect
Strategic Considerations • A better ploy is to coordinate the effort to rebuild operational systems with what are termed the “agents of change” • The aging of systems • The radical changing of technology • Organizational upheaval • Massive business changes
Methodology and Migration • Delta list: how the data model differs from existing systems • Impact analysis : how each delta item makes a difference • Resources estimate : how much will it cost to “fix” the delta item • Report to management : • What needs to be fixed • The estimate of resources required • The order of work • The disruption analysis
A Data-Driven Development Methodology • Why have methodologies been disappointing ? The reasons are many : • Methodologies generally show a flat, linear flow of activities. • Methodologies usually show activities as occurring once and only once. • Methodologies usually describe a prescribed set of activities to be done. • Methodologies often tell how to do something, not what needs to be done. • Methodologies often do not distinguish between the sizes of the systems being developed under the methodology. • Methodologies often mix project management concerns with design.development activities to be done. • Methodologies often do not make the distinction between operational and DSS processing, • Methodologies often do not include checkpoints and stopping places in the case of failure. • Methodologies are often sold as solutions, not tools • Methodologies often generate a lot of paper and very little design.
Data-Driven Methodology • What makes a methodology data driven ? • How is a data-driven methodology and different from any other methodology ? • Data-driven methodology does not take an application–by-application approach to the development of systems.
System Development Life Cycles • What we must do in SDLC ? • What a different between SDLC and data-driven methodology ?
A Philosophical Observation • Example
Operational Development/DSS Development • The data-driven methodology will be presented in three parts • METH 1 : is for operational systems and processing. • METH 2 : is for DSS systems and processing-the data warehouse. • METH 3 : describes what occurs in the heuristic component of the development process.