CS315: Session 3

Announcements:

• Final exam guide will be on web by Friday; see HyperNews group for details
• Final exam case will be on web by Friday
• Let's go for a beer after presentations on Wednesday!

Notes from Class (copied from slides)

• 6 Steps to Determining HOW to implement system design.
  • Identify several alternative strategies
  • Document each alternative
  • Estimate costs for each alternative (e.g., cost of development/purchase, installation, maintenance, training)
  • Perform a cost/benefit analysis for each given alternative.
  • Recommend a preferred alternative
  • Prepare a development plan.
• Industry wisdom suggests offering three alternatives: expensive, moderate, and cheap
• Defining Alternatives
  • No-brainer alternatives: Do nothing (note here that there are costs involved with doing nothing; the cost of the problem; legal/licensure costs, etc.)
  • Define system triggers and maximum response times to develop alternative views of system
  • Define automation boundaries (circles around processes/modules that are somehow related functionally or will share code)
• Costs and Benefits
  • Fiscal year--may be different from the calendar year, depending on company.
  • Prior to start of new fiscal year, functional areas asked to provide a list of planned projects and priorities for coming year. These should include the following information for each project:
    • what we want to do (project description)
    • why we want to do it (what problem will this solve?)
    • benefits of doing this project (cost savings, happy employees, etc.)
    • costs of doing this project
  • Project costs are separated into two categories: Development costs and operational costs.
  • Development Costs
    • cost of analysis, design
    • cost of new equipment and software development
    • cost of testing system
    • cost of traning system administrators and end users
    • site preparation costs (network connectivity; cooling system, etc.)
  • Operational Costs
    • on-going costs
    • maintenance on system/operating system
    • additional RAM and disk
    • personnel (system administrator(s))
    • outside service providers (off-site backup storage)
    • data and voice services
  • Costing Methodologies
    • COCOMO COnstructive COst MOdel
    • SLIM>
  • Person doing cost estimates should not be a stakeholder in project
  • Professional estimators for software development costs exist
  • Divide the project into its [functional] modules and determine cost to develop each module.
  • Model for determining programming time is: Programmer Months (K sub m) equals 2.4*lines of code (S sub k) to the power of 1.05 (sorry--no time to look up entity tags for super/subscript)
  • Once an estimate is complete, an auditor may come in to spot check estimate, talking with programmers, trainers, etc., to see how on-target estimate is from their standpoint.
  • Most jobs have accountability to the estimate included in the contract.
  • Always pad the budget with well-though-out contingencies for things like delays, equipment failure, price fluctuation, etc.
  • Always state the costs for a project as estimates--you can never know the actual cost of a project until you're finished with the project.