|
BACK TO 125 EXAMPLES in Engineering, Operations Management
and Computer Information Systems |
|
Do it once, do it right, and do it now. |
|
Back
to Lawson Computing Homepage
|
Apply as needed,
when needed. |
APPENDIX G
PARAMETRIC ESTIMATING SYSTEM CHECKLIST
APPENDIX G
PARAMETRIC ESTIMATING SYSTEM CHECKLIST
Elements of Good Estimating
Practice
The list that follows identifies
elements of good practice that support reliable estimating processes.
Questions:
Are
there other elements of good estimating practice that should be listed?
Are there other items of evidence
that indicate good practice that should be listed?
Should
any of the elements or items of evidence be reworded or eliminated?
Note: The objective here is to
identify elements of good practice that are distinguished, if possible, from
elements of good estimating processes. This means, among other things, that the
elements in the list should be independent of the estimating methods or models
used.
The element in this list should not
tell people how to estimate. They should simply provide guidelines and testable
criteria for doing it well.
Why
Do We Estimate Size, Cost, and Schedule?
To scope proposed tasks
To explore alternative system concepts
design to cost/budget
To explore alternative design
concepts
To explore alternative proposals for
enhancements and upgrades
To identify key design elements
To identify key process parameters
prioritize needs vs wants
To identify key assumptions
To identify and quantify
uncertainties
To identify tasks and their
relationships
To assess schedule feasibility
To identify, allocate and schedule
resources
To assess an organization’s ability
to perform within targeted costs
To evaluate the consequences of internal
and external constraints
To establish achievable objectives
To establish a basis for quality
service
To establish commitments
To bound the risk against customer
needs
To balance levels of risk against
customer needs
To provide a basis of successful
risk management
build vs buy analysis
To prepare successful proposals
To evaluate proposals from competing
bidders
To establish baselines for project
tracking
enhance/reuse vs redesign
analysis
To predict life-cycle costs
To predict returns on investments
To provide information for
establishing business and investment strategies
ELEMENTS OF GOOD ESTIMATING PRACTICE
Element
1. The objective (purpose) of the estimate
is stated in writing
2. The product to be produced is clearly
described
3. The tasks to be estimated are clearly
identified
4. People from related but different
projects or disciplines are involved in the estimating process
5. The validity of the estimate is
supported by relating it demonstrated performance on completed projects
6. More than one cost model or estimating
approach is used
7. Potential cost and schedules impacts
are estimated for all identified tasks
Evidence of Maturity
Information objectively captured in
historic database with a standard structure for ease of analysis
Estimates for product size and
content are supported by systematic engineering analyses
The terms and parameters that
describe the product enable comparisons to be made with other products
Checklists are used to identify the
elements and activities included (and excluded from) the estimate
Estimating and analysis team members
found in historical database
Values assigned to cost model
parameters are supported by comparisons to values used to describe completed
projects
The reasons for values assigned each
cost model parameter are documented in writing
Differences in results are analyzed
and accounted for
A structured process is used to
identify and scope technical risks
Uncertainties in values of
descriptive parameters are identified and quantified
The effects of uncertainties in
descriptive parameters are evaluated
8. Dictated schedules are analyzed for
impacts on cost
9. Estimates (or estimates to complete)
are updated whenever...
- changes
to requirements affect cost or schedule
-
constraints change
- actual values for product or process parameters are found to
be significantly different from those on which the plan is based
- tracking measures indicate that critical path tasks cannot
be completed as planned
10. The estimating origination has a method
(such as a database) for organizing and retaining information on completed
projects
Managers (and customers, where
appropriate) are informed of potential cost savings associated with alternative
schedules
Captured in historical database
Program manager uses the process to
manage the program and associated risks
Process flags management when risk
exceeds defined limits
Elements in the database are
recorded and described in ways that avoid misinterpretation
Schedule milestones (start and
finish dates) are described in terms of criteria for initiation or completion
Effort measures account for unpaid
overtime
The database is populated with a
useful set of completed projects
Cost models are used to provide
consistent frameworks (standard terms, WBS, parameters, etc.) for recording
historical data
Inconsistencies in historical data
are sought out and explained (this is perhaps best done with the same cost
models used for estimating)
11. Postmortems are held at the completion of
each project
- to ensure that events that affected cost or schedule are
described and recorded while still fresh in people’s minds
- to ensure that recorded data are valid
12. The emphasis throughout is on developing
consistency in describing completed projects and in relating new work to
demonstrated performance on those projects
Technical seminars and training
programs incorporate this information in a timely manner
The consistency achieved when
fitting cost models to completed projects is measured and tracked
The term "model accuracy"
(as in "the model made the estimate") is never used
INDICATORS OF ESTIMATING
CAPABILITY
What organizational support is
needed to successfully establish and sustain a reliable estimating capability?
The following checklist identifies
seven indicators of good support. For each indicator, it lists items of
evidence one can look for to help evaluate the quality of this support.
Questions:
Are
there other indicators of organizations support that should be listed?
Are
there other items of evidence that should be listed?
Should
any of the indicators or items of evidence be reworded or eliminated?
Note: The objective of this
checklist is to provide guidance to organizations that are seeking to establish
and sustain a successful estimating capability.
Indicators of Estimating Capability
- A Checklist for Successful Estimating Environments -
Indicator
1. Management acknowledges its
responsibility for developing and sustaining an estimating capability
2. The estimating function is funded
3. Estimators have been equipped with the
tools and training needed for reliable estimating
4. The people assigned as estimators are
experienced and capable
Evidence of Maturity
One or more managers have been assigned
responsibility for developing and sustaining the organization’s estimating
capability
The responsibility has been in place
for sufficient time to be effective
At least one person in the
organization has a standing assignment as an estimator
The funding provides for:
- establishing and sustaining a
corporate memory
- preparing estimates
- capturing data from ongoing and
completed projects
- acquiring and using estimating models
and tools
- educating
and training estimators
The funding is adequate (past,
present, and future)
The funding is stable
Estimators have up-to-date desktop
computing facilities (hardware and software)
Cost models and software such as
spreadsheets, databases, and statistical programs have been acquired or developed
Estimators have received training in
the cost, schedule, and size models they use
Estimators have received training in
estimating and model building
Independence/objectivity
The estimators have professional experience/
knowledge with the processes whose costs are estimated
5. The estimating capability of the
organization is quantified, tracked, and evaluated
6. Recognition and career paths exists
such that qualified people want to become estimators
7. Estimators help quantify and track
progress in software process improvement
Estimators have educational
backgrounds that support quantitative analysis as well as qualitative
The average years of estimating experience
among people assigned as estimators is computed and tracked
Consistent methods are used for
capturing and recording information from completed projects
Cost model calibrations are
up-to-date
Estimators participate in
professional activities or societies related to estimating
The people assigned as estimators
are viewed as a repository of estimating expertise
Management tracks and reviews the
effectiveness of its estimating capability
- what is
working well
- what’s not
working well
- opportunities
for improvement
Estimating is seen by both employees
and managers as a career-broadening assignment
Previous estimators have moved on to
positions of equal or higher responsibility
People volunteer to be estimators
Cost models are used to account for
factors that make projects different, so that process improvements can be
meaningfully measured and compared
Trend analyzed derived form cost
model calibrations are used to track changes in the organization’s processing
and performance parameters
Cost models are used as on-going
tools in managing program execution
A Manager’s Checklist for
Validating Cost and Schedule Estimates
When you (or your boss) receive a
cost or schedule estimate, what should you look for to determine your
willingness to rely on that estimate?
The checklist on the following pages
identifies key issues that have been identified as important to estimates we
can trust. Each issue is associated with elements of evidence that, if presents
support the credibility of the estimate.
Question:
Are
there other issues that you (or your boss) look at?
Are
there other issues that you should be looking at?
What evidence relative to any of
these issues would support you willingness to rely on an estimate?
Should
any parts of the present checklist be reworded or eliminated?
Note: The objective of this
checklist is to provide operational guidelines that help people evaluate the
credibility of cost and schedule estimates for software projects.
A secondary objective is to motivate
and guide organizations toward improving estimating processes and practices.
|
BACK TO 100 examples in Business, Operations and
Engineering. |
|
Do it once, do it right, and do it now. |
|
Back to Lawson Computing Homepage |
Apply as needed,
when needed. |
