Presenter – Tim Peek (TenStep)

Fear with estimates is that they will be inaccurate, but that’s just what an estimate is – a guess.  You’ll only know if your estimate was right when you’re done.

A lot of the information to build estimates comes from historical data.  Keep estimated vs. actual to determine estimation success

Estimates also give a yardstick as to how well you’re doing.

ROI is all about estimates, comparing the estimate to the value of the end product

Estimate is a judgment of size, number, etc. that needs assessment

Estimating is concerned with the prediction of uncertainties.  It is more dignified than fortune telling, though not always more accurate.

• Project Estimating
  • Effort (NOT duration)
    • You can’t determine duration until you figure out the effort needed
  • Cost
  • Schedule
• Why is it important?
  • Supports decision-making
  • Provides an ability to deal with the unknown
  • Determines what actions we see as safe and risky
    • Hiring
    • Spending
    • Lifespan of equipment
• Preparing for the Estimate
  • Determine estimating goals and tradeoffs
    • Quality
    • Cost
    • Time
  • Document the prior estimating assumptions and risks
  • Distinguish between effort and duration
    • I can have this activity done in 2 weeks.
    • This activity will take 40 hours
• Levels of Accuracy
  • Determine if there IS a level of accuracy requested or required (+/- 50%, SWAG, WAG)
• Estimate the Effort

• Preparing for the Estimate
  • Avoid estimating what you do not understand or know
  • Get a clear picture of the work you need to estimate
  • Determine if full life-cycle costs are required
  • Determine the resources covered in the estimate
    • Immediate project team
    • Clients
    • Vendors
    • Cross functional resources
• Estimating Techniques
  • Previous History
  • Analogy
  • Ratio
  • Expert Opinion
  • Delphi – Group of Experts via Questionnaire
  • Parametric Modeling
  • Work Breakdown Structure
  • PERT ((optimistic + 4x median + pessimistic)/6)
• Estimating Errors
  • You underestimate the size of the deliverables
  • You don’t include all of the activities required
    • Documentation
    • Project Management
    • Training
      • You commit to an estimate that is too low
  • You estimate based on building good quality in the first time
  • You do not manage quality, and don’t build quality control or QA activities into the schedule
    • You have more testing errors and more rework required
  • The client wants it done as quickly as possible
  • Your manager wants it done as quickly as possible
  • You think it can be done quickly, IF EVERYTHING GOES WELL
    • You commit to an estimate based on best-case
  • The client wants it done as quickly as possible
  • The client has a fixed amount for the budget
  • You think there is a chance you can get it done within available budget
    • You commit to an estimate based on available funding
  • The client tends to think the work is simple
  • The workers think they can do more than they can
  • The project manager does not take all the intangibles into account (estimating error, risks, problems, etc.)
    • You underestimate the work
  • You were burned on a similar project
  • You really don’t want to do the work
  • You tend to be pessimistic to begin with
    • You overestimate the work and hope it gets cancelled
  • Understanding common errors and not repeating them leads to more accurate estimates
• Estimating Effort, Duration and Cost
  • Estimate effort hours first
  • Duration estimates are next, based on known and unknown resources
  • Cost estimates are created after the rest of the schedule is completed
• The Estimate is Too High
  • The estimates are not arbitrary
  • Ask for more time to do more accurate and detailed estimate
  • You must balance the quality (effort), cost (budget), and time (schedule)
  • Look for ways to reduce costs using same effort
    • Less expensive resources
    • Older equipment
    • Internal instead of external training
  • Look for ways to reduce effort while still delivering
    • JAD sessions for requirements
    • Outsourcing
  • Look for ways to reduce the scope of work
    • Cut out less important reqs
    • Defer to later iteration
• Best Defense – Preparation
  • The Estimating Packet
    • You understanding of the work
    • The process used to prepare the estimate
    • The estimating technique(s) you used
    • A summary of the estimate
      • Effort, duration and cost as appropriate
    • The level of uncertainty
      • Estimating contingency
    • The estimating assumptions
    • The detailed estimating information
      • An appendix