estimation - the next level - and beyond
DESCRIPTION
IT estimation must make a move from size estimation that is translated to cost to an integral cost estimation practice. This is supported by the Basis of Estimate, a joint standard from NESMA and AACEi. Added is a special welcom for the IWSM 2014 in Rotterdam.TRANSCRIPT
EstimationThe Next Level
Ton DekkersIWSM – Ankara – October 25th 2013
NEtherlands Software Metrics users Association
Ton Dekkers - RolesNetherlands Software Metrics Association (NESMA)
President
International Software Benchmarking Standards Group (ISBSG)Past President
Common Software Measurement International Consortium (COSMIC)International Advisory Committee
Dutch Association of Cost Engineers (DACE)WG Parametric Estimation
Southgate Pedestrian Bridge, Melbourne
Estimation conceptsMost common
techniquesExtrapolation from ActualsExpert Opinion
Cost Estimating
The process of collecting and analyzing historical data and applying quantitative models, techniques, tools, and databases to predict the future cost of an item, product, program, or task
Purpose of cost estimating:Translate system/functional requirements associated with
programs, projects, proposals, or processes into budget requirements
Determine and communicate a realistic view of the likely cost (effort, schedule) outcome, which can form the basis of the plan for executing the work
A Bridge to the Future
EstimateHistorical data Time
nowSource: ICEAA training
Cost Estimation TechniquesAnalogy
Build-Up
Parametric
Parametric Estimating - ProcessCollect Data
Relevant, Reliable
Normalise DataCost level, activity level
Determine correlationsValidate correlations
R2 > 0.8 is useable
Adjust Data Set when necessaryDefine CER/EEREstimate the new object
NOW: CEBoKCost Engineering
Body of Knowledge
2012ISPA & SCEA
are merged intoICEAA
www.iceaaonline.org
About• Association for the Advancement of Cost Engineering -
International
• A not-for-profit organisation• Recommended Practices
17R-97: Cost Estimate Classification System34R-05: Basis of Estimate40R-08: Contingency Estimating: General Principles42R-08: Risk Analysis and Contingency Determination Using Parametric Estimating
• CertificationCertified Cost Consultant™ (CCC™)Certified Cost Engineer™ (CCE™)Certified Estimating Professional™ (CEP™)
• www.aacei.org
Simplified Estimation Model
hours (& money)
measures
risk analysis
risks
consequences
productivity
size
gross hours
influences
Basis of Estimate Quantity Metrics: excavation and backfill quantities, concrete
volumes, piping quantities, ... These may be organized by facilities, process train or manufacturing unit.
Basis of Estimate – Software Services Requirements: number of use cases, number of backlog items,
... Functional size: Function points
Measurement methods: IFPUG, NESMA, COSMIC, FiSMA, … Technical size: (source) lines of code, number of interfaces,
modules, … Service size: number of incidents, tickets, users, locations, …
These may include expected error range, level of accuracy and method of ‘measuring’ (e.g. detailed, extrapolated, estimated, derived)
Size
Basis of Estimate for Software Services
Generalaspects
Basis
Risk
Mitigation
Quality
Mapping to NESMA interest areas
Sizing BasisRequirements
Functionaltechnical
Effort Basisdelivery
constraints, service levels
Planning Basis
Working time standby
Cost Basismethods and
sources , units
BenchmarkingComparisons to
similar engagements
The Tax System Case Study
Basis of Estimate in Practice
H
A
L
na
L
A
H
Good
Poor
Conclusions from supplier perspectiveEstimation (validation)
Consistent structure (e.g. Basis of Estimate)Embedded process
BenchmarkingValidation Estimate / ProposalHistorical data (Internal/External)
MetrificationConsistent approachAuditable calculations (e.g. tool-based)
Management & ControlMetrification (direct data collection)Re-estimation (reflecting direct data)Risk Control
Estimation : The next level
EstimationThe Next Level
And BeyondFrank VogelezangIWSM – Ankara – October 25th 2013
NEtherlands Software Metrics users Association
The next level and beyondWidening the scope from sizing, to cost
drivers, through cost estimation relations to estimating, project control and historical benchmark data.
In cooperation with others like ISBSG, MAIN, DACE, PMI
Products that can be of interest outside the Netherlands will be made available in English
Active working groups with short cycles to deliverEstimation Measurement StandardsEstimating Packaged SoftwareCOSMIC Approximation
