Bsad Principles of System Development

8/2/2019 Bsad Principles of System Development

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Divide and Conquer All systems are part of larger systems (called super-systems). Virtually all systems contain smaller systems (called subsystems). We divide a system into its subsystems in order to more easily conquer

the problem and build the larger system. By dividing a larger problem (system) into more easily managed pieces

(subsystems), the analyst can simplify the problem-solving process

Establish Standards a. Enterprise IT Architecture sets standards that serve to direct technology

solutions and information systems to a common technology vision orconfiguration, which typically standardized on the ff:

database technology - database engine and platform) software technology - application devt environment languages, and interface technology - Windows components or web languages) b. Given the standards, all IS projects are constrained to implement new

systems that conform to it (unless otherwise approved)


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Document throughout Development Avoid post-documentation Documentation provides o Enhances communication and acceptance o Reveals strengths and weaknesses

o Stimulates user involvement o Reassures management about progress

Justify Information Systems as Capital Investments In considering capital investments, two issues are addressed in IS: o For any problem, there are likely to be several possible solutions

o Evaluate each solution for feasibility, especially for its cost-effectiveness ISs are recognized capital investments, thus, it is driven by enterprise

planning, which does entail the creation of strategic info systemsplanthat identifies and prioritizes IS devt projects


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Dont Be Afraid to Cancel or Revise Scope

a. Dont throw good money after bad b. Use the creeping commitment approach to systems devt that installs feasibility checkpoints into

systems development methodology c. At each checkpoint, feasibility is reassessed and all costs are considered sunk d. At each checkpoint also, the ff are considered: Cancel the project if it is no longer feasible

Reevaluate and adjust the costs and schedule if project scope is to be increased Reduce the scope if the project budget and schedule are frozen and not sufficient to cover all

project objectives

Manage the Process and Projects Process management an ongoing activity that documents, teaches, oversees the use of, and

improves an organizations chosen (the process) for systems development. Processmanagement is concerned with phases, activities, deliverables, and quality standards that shouldbe consistently applied to all projects

Project management ensures that an information system is developed at minimum cost, withina specified time frame, and with acceptable quality (using the standard system developmentprocess or methodology)

Process and project are influenced by quality management, wherein quality standards are builtinto a process to ensure that activities and deliverables of each phase will contribute to thedevelopment of a high-quality IS


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Design Systems for Growth and Change

Systems should be designed toaccommodate both growth and changing

requirements Entropy term coined by system

scientists to describe the natural and

inevitable decay of all systems over time An obsolete system needs to be

replaced


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Get the owners and users involved Valerie should have insisted on getting the users involved, and if

the owners continually declined those wishes, elevated the matter tomanagement.

Use a Problem-Solving approach To save time they decided to skip the survey, study, definition,

configuration, and design phases and go straight to construction.

Divide and Conquer The project was not divided into sub-systems in order to more easilyconquer the problem and build the larger system.

Establish Phases and Activities Based on the narrative no formal mechanisms of

assigning/identifying phases and activities was used.


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Establish standards for consistent development and documentation This was not done either for the sake of time and money.

Justify systems as capital investments The document they called a feasibility report was actually a proposal to implement the

only solution they investigated. When a single solution is presented, it is easy to beover-optimistic and over-committal. No alternatives were investigated.

Dont be afraid to cancel or revise scope The Creeping Commitment approach to have multiple feasibility checkpoints where

the analyst should consider cancellation, reevaluation of costs, and reduction ofscope. There were no feasibility checkpoints and once they had already spent$150,000 they felt if stupid to cancel the project. A fundamental rule of finance is that

all money spent so far is sunk - it can't be recovered. You don't waste new moneytrying to salvage a disastrous investment.

Design systems for growth and change Since there wasnt a formal design phase, this was never addressed.

Documents

Bsad Principles of System Development