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What does
r2ESTIMATOR estimate?
What is the basis of the math behind
r2ESTIMATOR?
What are r2SEF categories and profiles?
Can
r2ESTIMATOR emulate the behavior of exiting models such as
COCOMO?
Where do you get the data to create r2SEF categories and
profiles?
Can we calibrate
r2ESTIMATOR with our own data and how is that
done?
Does
r2ESTIMATOR recognize different size metrics?
How does
r2ESTIMATOR handle risk?
What is a Ross chart?
Can
r2ESTIMATOR model activities other
than software construction?
Does
r2ESTIMATOR have online help?
What export capabilities does
r2ESTIMATOR have?
When exporting to Microsoft Project, what gets exported?
Can
r2ESTIMATOR be integrated with other tools?
What are the minimum computer requirements for running
r2ESTIMATOR?
What does
r2ESTIMATOR estimate?
r2ESTIMATOR estimates cost, schedule, effort, staffing, reliability
(defects), and risk (probability of success).
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What is the basis of the math behind
r2ESTIMATOR?
r2ESTIMATOR implements the r2 Software Estimating Framework (r2SEF); a
collection of generalized equations developed by Mike Ross that builds
on original work done by Barry Boehm (COCOMO), Randy Jensen (Seer), and
Larry Putnam, Sr. (SLIM) in the late 1970s and early 1980s. Their early
work was based on data and assumptions that are now at least 25 years
old. In the meantime, data from many thousands of projects have since
been collected and offer an opportunity to revisit these old assumptions
and relationships. The r2SEF set of equations contain several variables
(exponents and multipliers) that provide the flexibility necessary to
model the increasingly wide diversity of projects suggested by all this
new project data.
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What are r2SEF categories and profiles?
The flexibility of the r2 Software Estimating Framework (r2SEF) lies in
its notion of categories and profiles. An r2SEF category
is a specific setting of certain r2SEF equation variables, the values of
which are computed from a collection of related projects' historical
data. In other words, an r2SEF category represents a unique software
estimating model. An r2SEF profile is a specific setting
of certain r2SEF equation variables that characterizes a particular
project within some category.
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Can
r2ESTIMATOR emulate the behavior of exiting models such as
COCOMO?
Yes. The flexibility provided by the r2SEF categories and profiles
allows for the inclusion of other models in the framework.
r2ESTIMATOR
currently includes categories, profiles, and parameter input dialog
boxes that specifically support COCOMO 81, COCOMO II, the Jensen Model
(Seer), and the NordenPutnamRayleigh (NPR) Model.
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Where do you get the data to create r2SEF categories and
profiles?
r2Estimating, LLC continuously searches for and attempts to obtain
historical project data from various sources. These sources include data
for sale such as that from the International Software Benchmarking
Standards Group (ISBSG); public domain data such as that collected by
various agencies within the US government; data contained in published
books, papers, and articles; data implied by public domain models; and
data collected during consulting engagements. All of this data has been
used to create a basic set of r2SEF categories and profiles, which we
include in each r2Estimator release; however, users can create their own
categories and profiles based on their own collected data, a practice we
strongly encourage.
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Can we calibrate
r2ESTIMATOR with our own data and how is that
done?
Yes. If you have completed project data that includes size (content),
effort (labor), duration (time), and postdelivery defects (optional),
you can perform a fairly simple data regression process (or we can do
this for you) to create and add a new r2SEF category to your
installation of
r2ESTIMATOR.
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Does
r2ESTIMATOR recognize different size metrics?
Yes. The nature of the r2SEF set of equations and the process used to
create r2SEF categories and profiles is such that any reasonable size
metric can be used to quantify the content of a particular software
product. The basic set of categories included with
r2ESTIMATOR assume
size measured in either logical Source Lines of Code (SLOC) or
International Function Points Users Group (IFPUG) Unadjusted Function
Points (UFPs); however, when users create their own categories, they can
choose to use any size metric that they deem appropriate for their
particular type and style of development.
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How does
r2ESTIMATOR handle risk?
r2ESTIMATOR expresses the risk associated with a key management metric
output value (duration, effort, cost, and defects) in terms of its
confidence probability (probability of meeting or exceeding the value).
For example, I estimate this project will take two years to complete and
I am 70% confident in this estimate; in other words, there is a 70%
chance that the project will complete in two years or less. In order to
provide this level of risk information, for each Work Breakdown
Structure (WBS) element key management metric,
r2ESTIMATOR inputs an
uncertainty range (distribution of possible outcomes) provided by the
user in the form of a [Lowest, Most Likely, Highest] triple.
r2ESTIMATOR
performs all of its estimation calculations with these uncertainty
ranges using probability distribution (random variable) mathematics
assisted by Monte Carlo simulation techniques. The results are key
management metric outputs expressed in the form of probability
distributions that show the range of possible outcomes and the
probability of success associated with each possible outcome.
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What is a Ross chart?
A Ross chart (invented by Mike Ross) is a graphical display of the
confidence (probability of success) and goal satisfaction of two
correlated random variables. Key features include:

A twodimensional Cartesian axis and
coordinate system.

A line or curve representing the
correlation between the two random variables.

Regions representing the functions limits
(reasonable range).

An interactive dynamic solution symbol
(blue circle) on the curve representing a specific instance
(solution) of the function.

Dynamic projection lines from the solution
symbol to each axis.

Dynamic cumulative distribution range
symbol on the axisends of each projection line (indexed in
increments of 10% confidence probability), each range symbol
representing its corresponding random variables confidence
probability distribution, its color determined by whether (green) or
not (red) the goal is satisfied within the confidence limit.

Interactive dynamic confidence limit (risk
tolerance) symbol (blue triangle) on each cumulative distribution
range symbol

Interactive dynamic goal symbol (blue
diamond) on each axis representing the goal value associated with
the corresponding variable.
In the above description interactive
means the element can be moved (dragged). Interactive elements, by
convention, are blue. Dynamic means the element moves in real
time as the result of some other real time element movement.
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Can
r2ESTIMATOR model activities other
than software construction?
Yes.
r2ESTIMATOR includes a rich set of Work Breakdown Structure (WBS)
element types in addition to software Construction that include
Decomposition, Integration, UserDefined, Cost Only, Milestone, Summary,
and Project Summary. These key metrics of these elements can be
specified as fixed amounts or as percentages of associated elements.
This set of element types allows you to model things that may not be
included in a basic software estimate like systems engineering, multiple
levels of requirements specification, multiple levels of integration,
program management, hardware and infrastructure development / purchase,
testing environment hardware and software development / purchase,
installation and deployment, user training, operations and maintenance
support after delivery, etc.
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Does
r2ESTIMATOR have online help?
Yes. The F1 key launches
r2ESTIMATOR online help. Additionally, all
r2ESTIMATOR dialog boxes contain a Help button that launches online help
specifically related to that particular dialog box. This
contextspecific help includes parameter help for COCOMO 81, COCOMO II,
the Jensen Model (Seer), and the NordenPutnamRayleigh (NPR) Model.
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What export capabilities does
r2ESTIMATOR have?
r2ESTIMATOR provides three distinct types of export: chart and report
image export via the Microsoft Windows clipboard, customizable data
export report to an XML file, and export to Microsoft Project.
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When exporting to Microsoft Project, what gets exported?
r2ESTIMATOR's export to Microsoft Project includes the entire project
element hierarchy with schedule, effort, and cost information associated
with each element. All of this is written to an XMLformatted file that
can be opened by Microsoft Project.
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Can
r2ESTIMATOR be integrated with other tools?
Yes. r2Estimator's project files and default files are formatted in XML
which gives users open access to any
r2ESTIMATOR project's inputs and
outputs.
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What are the minimum computer requirements for running
r2ESTIMATOR?
To install and run
r2ESTIMATOR, you will need:
 Microsoft Windows 2000, NT 4.0 or later, XP, or Vista
 At least 128 MB RAM
 A monitor capable of displaying at least 800 x 600 pixels (1024
x 768 is recommended for the best display) with 256 colors and 96
dpi fonts (default small fonts). Large fonts will work provided the
monitor is set to display more than 800 x 600 pixels.
 CDROM drive for installation
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