UNLEASHING THE POWER OF FUNCTION POINT ANALYSIS

Transcription

1 Paul Radford CHARISMATEK Software Metrics UNLEASHING THE POWER OF FUNCTION POINT ANALYSIS FPA across the Software Lifecycle - the critical model 1

2 CHARISMATEK Software Metrics Who We Are and What We Do Australia s flagship company for the provision of software tools and consulting and training services in the area of functional size measurement: Software Sizing, Estimating & Benchmarking Contracts & Suppliers Software Process Improvement Software Capability Assessment and Gap Analysis Portfolio Management Developers of the Function Point WORKBENCH, the world s leading software tool supporting the Function Point Analysis technique for sizing and evaluating software. In the business of software metrics since 1991 and based in Melbourne. 2

3 Interest in Functional Sizing Measures A Truly International Coverage! Sweden Finland Iceland Denmark Lithuania Netherlands Russia UK Poland Germany Croatia France Austria Bulgaria Belgium Switzerland Romania Japan Spain Italy Turkey Czech Republic Portugal Greece China Egypt Pakistan South Korea United Arab Emirates India Hong Kong Saudia Arabia Thailand Malaysia Singapore Philippines Mexico Canada USA Panama Trinidad & Tobago Uruguay Venezuela Indonesia Brazil South Africa Australia Chile Argentina New Zealand 3

4 Functional Size Measurement Critical Advantages! Software Product Functional Size Measurement Software Functional Size 650 Function Points Software Project Functional Size is a measure of software size that: focuses on the functionality the software delivers to its users is independent of how the software is built eg language, technology, methodology can be determined early in the development life cycle is a reliable predictor of effort - and hence cost - to build and support the software provides a Standard Notation and Definition based upon an objective approach for software sizing (IFPUG and ISO Standards) 4

5 Functional Size Measurement One Common Language! Software Product Functional Size Measurement Software Functional Size 650 Function Points Software Project Functional Size is a measure of software size that: focuses on the functionality the software delivers to its users provides a definition, within a known technical environment, that is meaningful and relevant to the IT Developer ONE MODEL ONE LANGUAGE IT <-> BUSINESS 5

6 The role of Functional Size Measurement in the Software Development Life Cycle Requirements Assessment Functional Baseline Project Estimation Scope Management Status Monitoring Compliance Assessment Support Resource Forecasting Enhancement Projects Feasibility Study Requirements Analysis Design Construction Testing Implementation Functional Size Measurement Production Enhancement - a Role in a Range of Activities Throughout the Software Development Life Cycle -a Critical Component of Successful Software Development 6

7 Functional Size Measurement The Basis for Software Management Software Product Functional Size Measurement Software Functional Size 650 Function Points The Quantified Functional Model provides: A Structure for Definition Software Project A Reliable Basis for Estimation A Basis for Communication/Negotiation A Framework for Project Control A Means for Assessing Impact of Change An Integrated Link to Support Metrics 7

8 Assessing, Clarifying & Negotiating Requirements Feasibility Study Early Life-Cycle Estimates Function Requiring Clarification Preliminary Functional Model: First Cut. Consists of: Some clearly specified user functions Other user functions requiring clarification Basis for negotiation on project functionality Underwrites the business case Indicative Project Size Multiplier for No of Instances of a Function Indicative Functional Size: Basis for very early life-cycle estimation 8

9 Assessing, Clarifying & Negotiating Requirements Requirements Analysis Requires Clarification large! Rework Requires Clarification smaller! Specified HIGHER RISK! Specified LOWER RISK! Functionality Requiring Clarification from Client 9

10 A Software Project Functional Baseline Requirements Analysis Project Size Sub- System Size Detailed Functional Model: All agreed user functions assessed, classified and sized Cross references to other project documentation Sharing the Vision: Mutually Understood Agreed baseline for estimation, tracking and control and scope management Auditable, verifiable and defensible Fully Assessed Count: Entire project Project sub-systems Alternative project views 10

11 Tracking Requirements Requirements Analysis In order to track Requirements, each function should be cross referenced to specifications and work products. In this example, user functions are cross-referenced to their use case specifications. 11

12 Estimating Project Effort and Cost Estimation Productivity Sinks & Rates (Hrs / FP) Multiple Productivity Sinks & Rates: Development languages and environments: eg Java 14.2 Hrs / FP,.NET 17.3 Hrs / FP, SQL Server 7.5 Hrs / FP Assign user functions to productivity sinks to develop detailed estimates Effort & Cost Estimates 12

13 Estimating Project Effort and Cost Estimation Productivity Sinks & Rates (Hrs / FP) What productivity will we achieve on the planned project? Accounting Based Upon: Own History Design Approach Industry Benchmarks Tools/Consultants Expertise Further Refined Project Views: Functional priorities: eg essential versus optional Development releases: eg 1st, 2nd, 3rd releases Effort & Cost Estimates Cross Validation: Task based estimate comparison 13

14 Estimating Project Effort & Cost Estimation Programming Environment based Productivity Sinks and Rates Effort and Cost Estimates 14

15 Estimating Project Effort & Cost Estimation Effort and Cost Estimates 15

16 Modeling Enhancement Projects Enhancement Enhancement Size 66 Test Scope Size 89 Application Size 173 after Enhancement Application Functions Added or Changed by Enhancement Project Enhancement Project Size Enhancement Functional Model: Functions added, changed, deleted or of interest to regression testing Enhancement Functional Size: Size of enhancement project Size of test scope Size of application baseline after project completion Application Baseline: Automatically maintained after each enhancement Represents an application s current functionality and size 16

17 Managing Project Scope Requirements to Implementation Functionality Added during Detailed Design Phase When Function Introduced Project Scope Monitoring: Assess scope and size of project at major milestones and update the model Compare actual versus expected size and scope Early Scope Blowout Identification: Identify unacceptable scope increase early Highlight magnitude and nature of scope increase Impact of Scope Change Assessment: Estimate potential additional development costs and schedule increase Renegotiate project scope Understand where and why change occurs 17

18 Managing Project Scope Requirements to Implementation Unacceptable Project Size and Scope Increase New Project Size after Negotiation and Rescoping 18

19 Monitoring & Controlling Project Status Requirements to Implementation Construction Phase States Current Function Status within Construction Phase Project Status Functional View: Assess the status of user functions within a project phase Alternative to traditional percentage complete view of project status Enhanced Developer and Client Communication: Easily maintained by developers / technical staff Easily understood by clients / business 19

20 Monitoring & Controlling Project Status Requirements to Implementation Snapshot of the Current Functional Size within each Construction Phase State 20

21 Historical Analysis/Drilldown Counts for an Application System Application Counts 700 Project Counts Projects Core Functions Sales Reports Security Feasibility Requirements External Design Internal Design Implementation Production Software Development Life Cycle Phases Audit, Internal Benchmarking, Patterns 21

22 Benchmarking, Productivity Analysis Completing the Cycle Application/Environment Benchmarks & Comparative Analysis Development Benchmarks Capability Analysis Process Personnel Environment Size Productivity Sinks Support Benchmarks Capability Analysis Size Application Complexity, Age, Volatility, Data & Client Volume 22