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Estimation SPR Introduction.

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Presentation on theme: "Estimation SPR Introduction."— Presentation transcript:

1 Estimation SPR Introduction

2 Building a Business Case for Estimation

3 “Staggering Stats” The Standish Group “Chaos” report shows:
31.1% of projects will be cancelled before they ever get completed. 52.7% of projects will cost 189% of their original estimates. The cost of these failures and overruns are just the tip of the iceberg. The lost opportunity costs are not measurable, but could easily be in the trillions of dollars. Only 16.2% for software projects that are completed on-time and on-budget. . Even when these projects are completed, many are no more than a mere shadow of their original specification requirements. Projects completed by the largest American companies have only approximately 42% of the originally-proposed features and functions. The above findings have been consistent for the last 25 years

4 Estimation Why do we need to estimate?
To work out how much effort & cost might be involved to deliver a project often based on incomplete input data that may be incomplete or uncertain. To plan To run through scenarios to determine feasibility Why is estimation of software projects difficult? Types of Estimation technique may be based on developer opinion, apply Methods like function block counting or broadband delphi or use Rules of Thumb - all are mostly based on guesswork, personality and resource experience, can be time consuming and are often inconsistently applied. “Accurate software estimating is too difficult for simple rules of thumb.” ~ Capers Jones, 1991 How do we introduce more accurate estimation? Through the introduction of a method to determine the size of the functionality (function point analysis) to be delivered by a software project and using this as a base from which effort to deliver functionality can be estimated. This can allow for a more scientific approach and consistently applied process to estimating effort and cost.

5 Generic Problem Statement (Summary)
There is no standard estimation process Project managers make use of their own tools, methods and processes to come up with estimates. These are therefore inconsistent and often dependant on the experience and knowledge of the Project Manager There is no central repository for recording estimates Assumptions therefore cannot be traced and this problem is compounded by turnover of project management staff. Initial estimates that drive the initial budgeting process tend to be significantly lower then final budget/actuals. History shows the Projects planned for the release miss their release dates. This will increase costs and project delivery timelines. A large percentage of active projects have no baseline in place. Estimation is inconsistent and ever changing

6 Generic Problem Statement - Detail
People Lack of clarity around who does the estimates and who is responsible for the estimates Skills not adequate to deliver accurate estimates Limited understanding of the estimation process and terminology Process Business do not understand the estimation process and their input into this process. Lack of clearly defined scope management process and principles from an estimation perspective Estimation is dependant on the forecasting and budgeting process, which is financially driven rather than size driven. Systems Lack of historical information Lack of industry benchmarks Lack of a central repository for storing estimations and assumptions. Practice Estimation process is dependant on the requirements process, which is new and slowly maturing within the many environments. No standards exist in terms of sizing (Function Point count) The above issues result in variances in time, cost and effort when compared to actuals

7 Formal Software Project Estimation
SPR KnowledgePlan SPR KnowledgePLAN® Formal Software Project Estimation

8 SPR History Software Productivity Research (SPR) was founded in 1984 by Capers Jones, an internationally recognized consultant, speaker, author and seminar leader in the field of software management. SPR is a worldwide provider of consulting services that enable organizations to compete more effectively through the predictable, on-time delivery of high-quality software by focusing on software estimation, measurement, and assessment. Their services help companies manage the software development process for maximum productivity, performance, and quality. SPR’s clients include many of the Global 1000 companies, representing all major software environments including systems, IT, commercial, military, and government. They focus on capturing and analyzing the software practices of Best in Class organizations - those recognized for outstanding quality and service. In addition, they help software organizations achieve higher performance as they progress on the road to excellence. Headquartered in Hendersonville, North Carolina, with representation throughout the US, South America, Europe, Asia and now Africa, SPR has unparalleled expertise in estimation, benchmarking, measurement, function point analysis, and process assessment. They have been providing superior products and services in these areas longer than any other company in the field today, and they use this experience effectively to enhance our clients' capabilities.

9 What is SPR KnowledgePLAN?
KnowledgePLAN is a parametric estimation tool that uses historical data about projects correlated to Function Point size to produce detailed, bottom-up (micro estimation) predictions of software projects With SPR KnowledgePLAN you can: Determine SIZE - size your projects using three possible sizing methods Effort - Produce an estimate of effort, cost and resource required for a software project. Estimate Quality - Predict the total number of defects that will be introduced during various stages of the project Project Factors - Assess the influence of project factors such as product size and complexity, team skill sets, management style, tools, languages, methods, quality practices, and office environment Scenario Play - SPR KnowledgePLAN allows a software project to explore the cost/value implications of additional resources, more powerful languages, development tools, improved methods and other technical changes. - SPR allows approximation of functional size from which effort can be determined considering various of influencing project factors. Scenario play gives insight to the impact of these factors on effort and duration numbers to deliver approximated size.

10 SPR Knowledge Base Project Size Project Classification Project Type
14,531 projects in Version 4.3 (2009) Project Size Project Classification Project Type Large 23% Medium 50% Small 27% Enhancement 48% New 31% Maintenance 21% Systems 30% IT 45% Other 16% Commercial 10% © 2009, Software Productivity Research, LLC. Global Rights Reserved.

11 SPR KnowledgePLAN - Overview
Sizing Methods Environmental Attributes Software Project Types WBS

12 Key stages to Estimation
How does KnowledgePLAN support a 4 stage estimation process How big? How difficult? How capable? Which tasks? Sizing Complexity Capability Process Mitigated by tools and languages RISK must be properly assessed Waterfall Agile RUP Iterative-Spiral DSDM

13 SPR Sizing SPR support three different types of sizing methods.
Complexity Capability Process Sizing by Metrics Sizing can be input by various metrics: Function Points (Recommended) IFPUG/NESMA COSMIC FFP Mark II Object Points Estimated Function Points Technical (approximation) Function Points Logical System Lines of Code SPR support three different types of sizing methods. This allows organizations to align methods to specific inputs into estimation that become available through the Project Lifecycle More than projects in the Knowledge Base Sizing by Components Use a multi-tiered approach to sizing Estimate built from known values Approximation accuracy approaches that of FPA Combine with Size by Metric when more is known Sizing by Analogy Estimates can be made against a variety of software products in the table, further categorized by size (small/medium/large) The portions of enhancement projects that are New, Enhancement, Maintenance, and Conversion effort are recorded here

14 Estimation Stage - Complexity
Complexity factors are rated for projects Sizing Complexity Capability Process Algorithmic (“Problem”) complexity Correction for effort within the application boundary Structural (“Code”) complexity Quantitative scale describes recursive statements High complexity somewhat mitigated by high-level languages/skills Relational (“Data”) complexity Extent of data organization complexity High complexity somewhat mitigated by data modeling

15 Estimation Stage - Capability
Sizing Complexity Capability Process Technology Software tools and platform issues Technology Process Environment Personnel SOFTWARE QUALITY AND PRODUCTIVITY Product Process Development methods, quality assurance, testing, documentation Personnel Experience and skills of: managers, developers, users Product Hardware and software requirements, constraints, and architectures Environment Organization, office and physical environment

16 Estimation Stage- Process
Sizing Complexity Capability Process Tasks are selected by the model and may be adjusted Projects are made up of tasks for which deliverables are predicted based on historical information in each task category 134 task categories are available in the tool TASK CATEGORY Task 1 Task 2 Task 3 TASK CATEGORY Task 1 Task 2 Task 3 Requirements Designs Code Test cases Documentation TASK CATEGORY Task 1 Task 2 Task 3 Task 4 TASK CATEGORY Task 1 Task 2

17 Detailed reporting allows for easy interrogation of data

18 SPR Limitations It is not a substitute for good planning (it is only a part of it) Project managers still need to: Discuss, agree and monitor delivery with project resources Manage dependencies, issues and risks Manage their project calendar and resources pool Keep their plans updated and relevant! The tool has its limitations and cannot estimate: Estimate projects with no sizeable software development(SDLC) components Estimate on peripheral constraints and impacts to project cost and duration outside of what can be captured into the Tool (i.e.: infrastructural changes, resource unavailability, Fixed/CAPEX costs, delays, freeze periods).

19 Estimation - Processes

20 When do we estimate in the Innovation lifecycle & why?
Stage In Process: Beginning of the idea/concept phase. Stage In Process: Middle of Detailed Design (DD) which implies - no later than 6 weeks into Detail Design / End of Detail Design Stage In Process: End of High Level Design Stage In Process: Release into Production Innovation Project Lifecycle Idea Cloud / Concept Evaluation High Level Design Detailed Design Build, Test, Fix Implementation E E E Estimation by Analogy to assist with Pre-Execution Budget . Reason for Estimation For input around time, cost & effort estimates into the business case Reason for Estimation To review & revise the execution budget. To provide time, cost & effort estimates. Reason Actual vs Estimate Analysis To understand actuals & perform variance analysis from earlier phases in order to understand route cause of variances. To record historical data for future use by estimations of other similar projects going forward. E Optional Mandatory

21 What are the key inputs & documents?
Idea Cloud / Concept Evaluation High Level Design Detailed Design Build, Test, Fix Implementation E E E Inputs / documents New Idea Logged HL Business Requirements Business Requirements Specification n Project Close-out HL Architectural Design Process Definition Architectural Design Component Model Functional Specification Technical Specification Updated Documents Approved Business case Estimation EAQ Estimation EAQ Estimation EAQ Key SPR specific estimation documents required are the Estimation Environmental Assessment Questionaire This document allows for the rating of estimation attributes (Capabilities of dev team , involvement of business, quality assurance measures etc) It allows for dev teams to provide a view of perceived development complexity for both what is to be added as new, changed and re –added or changed as part of existing code. Estimation outputs Function point count (detailed complexity) Analogy Estimate Produced Component count (avg complexity) Tracked project Actuals vs Est. Estimation & Estimation report created

22 What technique do we use for estimation?
Stage In Process: Beginning of the concept phase Stage In Process: End of High Level Design Stage In Process: Middle of Detailed Design / End of Detailed Design Stage In Process: Release into Production Innovation Project Lifecycle Idea Cloud / Concept Evaluation High Level Design Detailed Design Build, Test, Fix Implementation E E E Technique - Analogy Optionally–using to size and estimate projects where very littlie information is available. Technique – Component Compile estimation input from all areas and collate for overall time & effort. Inputs from other Group Technology areas: High Level Work Breakdown Structure with expert based estimation Technique – Metric (FP count) Detailed documentation Detailed Work Breakdown Structure Technique Actuals versus Estimated tracking and comparison based off Function Point Counting Looking at actual project schedule Capture Actual value

23 What are our confidence factors for estimation in the different phases of the lifecycle?
Stage In Process: Beginning of the Concept Phase Stage In Process: End of High Level Design Stage In Process: Middle of Detailed Design / End of Detailed Design Stage In Process: Release into Production Innovation Project Lifecycle Idea Cloud / Concept Evaluation High Level Design Detailed Design Build, Test, Fix Implementation PLAYPEN (Existing Process apply) E E E E Estimation Confidence Factor 20-40 % Estimation Confidence Factor 50 – 60% Estimation Confidence Factor Middle of Detailed Design = 60% End of Detailed Design = 85% Estimation Confidence Factor Actual = 100% Confidence levels are dependent requirement & scope stability as well as the detail and accuracy of conceptual and detailed design documentation that is used as input into the estimation types. Highest confidence levels are achieved through estimation by Metric where functional sizing is done through the application of function point analysis. Analogy estimations can provide an accurate view however this remains a method through which functional size is approximated based on relating a projects intended functional object to very high level descriptions in the knowledgeBASE. In order for the upper end of the confidence scale to be achieved using analogy enterprise specific analogies would need to be created. In so doing the variability inherent with this type of estimation is reduced.

24 Estimation confidence
Build, Test, Fix Implementation Idea Cloud/ Concept Evaluation High Level Design Detailed Design ANALOGY METRIC (COMPONENT) METRIC CONFIDENCE 85% 60% 40% 20%


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