www.SoftwareMetrics.Com119 Function Point Training Instructor:
David Longstreet [email protected] www.SoftwareMetrics.Com
816-739-4058
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www.SoftwareMetrics.Com120 Two Day Schedule u Day One Function
Point Concepts Measurement Theory Estimating Models u Day Two
Function Point Case Studies More on Estimating Models
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www.SoftwareMetrics.Com121 Course Objectives u Understand and
apply function point concepts u Understand basics of measurement
theory u Introduction to software economics u Review/remember some
basic statistical concepts
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www.SoftwareMetrics.Com122 Estimate the Surface Area of a A can
of diet coke
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www.SoftwareMetrics.Com123 A different perspective
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www.SoftwareMetrics.Com124 Who is David Longstreet u Metrics u
Background u Clients u Research u Publishing u Teaching
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www.SoftwareMetrics.Com125 My Metrics Over 2 million frequent
flyer miles Consulted on every continent except Antarctica
Presented papers at conferences in USA, Europe, Middle East, Asia
and Africa
www.SoftwareMetrics.Com131 Website Metrics u About 15,000
unique visitors per month u Over 7,000 visitors view more than 5
pages u Over 1,000 visitors view more than 20 pages. u Free manual
is viewed over 15,000 times per month.
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www.SoftwareMetrics.Com132 Clients u Clients include Banking
& Finance, Aerospace, Retailers, Animal Food, Telephony,
Consulting Companies, Medical Research, Defense Contractors,
Automotive, Universities, Government Agencies and others u Some
clients: MasterCard, Amadeus, Ralston Purina, Lockheed,
Transamerica, DirecTV, Biologic, Accenture, Motorola, Nissan,
others
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www.SoftwareMetrics.Com133 Type of Work u Productivity
Assessments u Benchmark Studies u Estimating Models u Mergers and
Acquisitions u Venture Capital and Initial Public Offerings u
Outsourcing Agreements u Expert Testimony
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www.SoftwareMetrics.Com134 Learning from organizations
(ethology) u Collect both quantitative and qualitative data u
Observe behaviors, customs, rituals, myths and ways of life u
Examine artifacts and physical evidence u Build holistic picture of
organization u Trend the industry as a whole
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www.SoftwareMetrics.Com135 Worst Practices u No historical data
u Failure to monitor and report status u Creating analysis
documentation after coding u Excessive and irrational schedule
pressures u Failure to establish clear acceptance criteria u Reduce
testing time to make schedule
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www.SoftwareMetrics.Com136 Research u Dale Jorgenson, Harvard
Business School Historical Study of Productivity Rates for Software
Development (1950 present). u Bureau of Economic Analysis Methods
of collecting and reporting software productivity rates based upon
Function Points. Measuring the IT Economy. u Securities Exchange
Commission
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www.SoftwareMetrics.Com137 Adjunct Professor (Avila University
MBA & Graduate Psychology) u Industrial Organization Psychology
u Managerial Economics u Statistics u Quantitative Analysis u
E-Commerce
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www.SoftwareMetrics.Com138 There are lies, dammed lies and
statistics. Mark Twain Hannibal, Missouri
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www.SoftwareMetrics.Com139 Negative things I have heard. u
Software Voodoo! u Figures won't lie but liars will figure u You
may prove anything with metrics.
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www.SoftwareMetrics.Com140 Scientific Method u Knowledge comes
from Systematic observation Measurement of particular variables
& events u Develop both descriptive & predictive metrics.
Descriptive: describes current environment Predictive: used to
estimate
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www.SoftwareMetrics.Com141 Theory of Measurement u The use of
numbers to represent events, variables and characteristics. t
Quantitative variables t Qualitative variables
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www.SoftwareMetrics.Com142
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www.SoftwareMetrics.Com143 What gets measured gets done u
Partially Correct u What gets rewarded gets repeated u Measurements
without consequences get ignored.
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www.SoftwareMetrics.Com144 Background Summary u Constantly
learning u Industry diverse client base u Geographically diverse
client base u Research/Publishing u Growing industry knowledge u
Better ways to teach and instruct
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www.SoftwareMetrics.Com145 Measurement Theory u Introduction to
measurement u Productivity u Scientific method u Historical
perspective u Introduction to software economics u The idea of
function points
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www.SoftwareMetrics.Com146 Measurement Theory u Concept not new
to many other disciplines Scientific Method u Relatively new to
software development
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www.SoftwareMetrics.Com147 Productivity u The output-input
ratio within a time period with due consideration for quality. u
Productivity = outputs/inputs
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www.SoftwareMetrics.Com148 Improving Productivity (reducing
unit costs) u Costs/FP u Hours/FP u We can mathematical reduce unit
cost by t Reducing Cost t Increasing FP produced
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www.SoftwareMetrics.Com149 Productivity u It is difficult
(maybe impossible) to reduce productivity by reducing cost. t Cost
/ FP u In fact, for each $1 reduction in cost increases cost/fp by
about $1.18
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www.SoftwareMetrics.Com150 Effectiveness v. Efficiency u
Effectiveness is the achievement of objectives u Efficiency is the
achievement of the ends with least amount of resources.
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www.SoftwareMetrics.Com151
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www.SoftwareMetrics.Com152 International Weights & Measures
u International weights and standards Standardization in 1863 u
Motivation for international weights & standards was driven by
trade and specifically international trade.
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www.SoftwareMetrics.Com153 Concepts from Industrial Revolution
u Management methods 1901 u Break - Even charts 1903 u Centralized
accounting 1908 u Total Quality Management 1950s
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www.SoftwareMetrics.Com154 Size of Largest Projects Since
1970
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www.SoftwareMetrics.Com155 Hours/FP Since 1970 (Unit Cost)
www.SoftwareMetrics.Com157 Failure Rates are High u 75% of
metrics programs fail. u 70 80% of people who try to stop smoking
do not succeed. u 60% of Alcoholics return to drinking. u 93% of of
those addicted to gambling gamble again within 1 year.
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www.SoftwareMetrics.Com158 If at first you dont succeed u The
most thoroughly accepted notions in psychology is the principle
that behavior eventually extinguishes if it is not followed by
reward. u What gets rewarded gets done!
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www.SoftwareMetrics.Com159 Software Economics Social Psychology
Economics Organizational Behavior Statistics Psychology Software
Development
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www.SoftwareMetrics.Com160 Software Economics u Study Prices
and Costs u Study Behavior u Study the whys u Comparative
analysis
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www.SoftwareMetrics.Com161 Inputs Outputs Storage All systems
have..
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www.SoftwareMetrics.Com162 Two Major Categories u Transactions
Inputs Inquiries (reads) Outputs (calculations) u Storage
Maintained Data Referenced Data
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www.SoftwareMetrics.Com163 Validity of Function Points u Face
Validity Does this make sense? u Predictive Validity Useful for
predicting effort, time, cost, other? u Convergent Validity Do FPs
move in same direction as LOC, Test Cases, Use Cases, Objects
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www.SoftwareMetrics.Com164 Face Validity u Does this idea make
sense? u Can a software application be sized by looking at
transactions and files? u Are there other items we need to
consider?
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www.SoftwareMetrics.Com165 Predictive Validity u Does function
points actually predict what it is suppose to predict? u To what
degree (how accurate) The effort required to implement 5,000 fp's
is more than 500 fps? How about 4,500 fps v. 5,000 fps?
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www.SoftwareMetrics.Com166 Predictive Validity (other inputs) u
How accurate is historical time reporting, staffing levels, defect
tracking? Hours Per Function Point Duration Per Function Point
Defects Per Function Point u How accurate are project plans?
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www.SoftwareMetrics.Com167 Convergent Validity u Function
Points x 1.2 approximates test cases. u Lines of Code divided by
100 approximates function points. Varies by language u Seems to be
a positive relationship between test cases and function points u
More staff is needed as function points increase.
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www.SoftwareMetrics.Com168 Measurement Theory u Introduction to
measurement u Productivity u Scientific method u Historical
perspective u Introduction to software economics u The idea of
function points
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www.SoftwareMetrics.Com169 Understanding Software Development
Costs u Large Projects u Marginal Cost u Interval Estimating v.
Point Estimating u Building Estimating Models u Samples v.
Populations u Industry Data
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www.SoftwareMetrics.Com170 Large Projects u Increasing Marginal
Cost As size increases unit cost rise. u Any large engineering or
construction project follows the same economic model.
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www.SoftwareMetrics.Com171 Marginal Cost u The change in total
cost attributable to a one-unit change in output. u The unit cost
of software is not fixed. u Unit cost changes as the size of the
project changes.
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www.SoftwareMetrics.Com172
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www.SoftwareMetrics.Com173
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www.SoftwareMetrics.Com174 Individuals Range of Productivity u
Range of individual productivity can be 100 times t An expert
developer may be 100 times more productivity than a novice. u True
for other industries as well Automotive Mechanics Carpentry Cake
Decorating Roofing
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www.SoftwareMetrics.Com175 Cake Decorating?
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www.SoftwareMetrics.Com176 Paying by the hour u What behavior
is encouraged. u What type of person is hired. By the way, cake
decorators charge by the piece of cake.
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www.SoftwareMetrics.Com177 Industry Data u $1,500 function
points with a margin of error of $500 t 90% confidence level u
Range is $1,000 $2,000 per function u Range in hours is 100 200
hours per function point.
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www.SoftwareMetrics.Com178 Transamerica Building u 499,000
square feet u $144 Million to construct u $290/Square Foot National
Average $102/Sq. Ft San Francisco Average $140/ Sq Ft.
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www.SoftwareMetrics.Com179 Comparative Costs Per Square Foot u
Office Space $69 - $290 u Warehouse $28 - $43 u Single Unit Retail
$46 - $71 u Depending on the type of software application being
constructed unit costs varies.
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www.SoftwareMetrics.Com180 Some Statistics u Range $28/Sq. Ft.
- $290/Sq. Ft. u Average $75/ Sq. Ft u Standard Deviation $54/ Sq.
Ft. u We see similar variations in software costs also.
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www.SoftwareMetrics.Com181 Many other Factors u Size is size u
All those other factors are part of the unit cost $/Sq. Foot $/
Function Point
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www.SoftwareMetrics.Com182 Samples v. Populations u You do not
have to FP count every single application to understand
organizational productivity! u You do not have to examine every
single project to understand organizational trends.
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www.SoftwareMetrics.Com183 Gathering Historical Data Samples v.
Population u Population your entire application portfolio u Sample
key projects/applications to help you understand the entire
application portfolio
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www.SoftwareMetrics.Com184 Random v. Selective u Select a range
of projects Best Worst In between u Need only 12 or so
projects
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www.SoftwareMetrics.Com185 How & What u To really
understand the quality of products you must first look at the
organization that produces the software. u How you do it & what
you do.
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www.SoftwareMetrics.Com186 Principles u It is not possible for
an unstable organization to produce consistent high quality
products. u It is not possible for an unstable organization
(inconsistent) to produce accurate estimates.
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www.SoftwareMetrics.Com187 Who makes software? u People are the
major input used to develop software. u Understanding human
behavior is important to understanding the software development
process. u What type of behavior is being encouraged?
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www.SoftwareMetrics.Com188
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www.SoftwareMetrics.Com189 Cost to Develop Software Planning
Testing/ Implementation $/FP to make changes Unit cost $/FP to make
changes Unit Cost >
