1. 1 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Software Estimating with Functional Metrics Scott Goldfarb Q/P Management Group, Inc. 10 Bow Street Stoneham, MA 02180 Tel:(781) 438-2692 FAX: (781) 438-5549 Webpage: www.QPMG.com QP Management Group, Inc.

2. 2 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Software Estimating with Functional Metrics The methodologies reflected in the enclosed material, including the benchmark comparisons, are confidential and proprietary information of Q/P Management Group, Inc. and are for the internal use of addressee only. QP Management Group, Inc.

3. 3 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Objectives - Estimating with Functional Metrics Provide a top down estimating approach that can be used early in the life cycle Base the estimate on customer requirements and constraints Consider the technical environment, project characteristics and past performance Communicate accurate estimates that can be easily updated as the situation changes

4. 4 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. A Top Down Estimating Approach Top Down Determine detailed estimates from available totals –Size functionality to be delivered –Based on past performance and quantitative information Functional Metrics Estimating model, and repository of past performance Generated estimates

5. 5 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Project Estimation Influences Functional Size Project Attributes Business Pressure Quality Cost Effort Schedule Estimating Process Technical Characteristics

6. 6 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Four Steps to Better Estimates 1. Function Point Analysis - gives the size of the project based on the user perspective of functional requirements. 2. Evaluation of Project Attributes - analyzes the factors, in addition to size, that impact the productivity of projects. 3. Establish Productivity Rating - analyzes size data and project attribute information in order to establish the appropriate productivity rate based on historical data. 4. Develop Estimate - develops and documents estimate of effort, cost and schedule based on the established productivity rate.

7. 7 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. The Estimating Process Prepare for the Estimate Function Point Analysis Evaluate Project Attributes Establish Productivity Rate Develop Estimate Communicate the Estimate Iterative Process Data Warehouse of Estimates & Actuals Estimate Step 1.Step 2. Step 3. Step 4.

8. 8 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Step 1: Function Point Analysis - Quantify Software Size External Interface Files Internal Logical File External Input External Output External Inquiry Application Being Considered Other Applications (EO) (EI) Functionality as viewed from the users’ perspective

9. 9 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Lines of Code versus Function Points Lines of Code Lines of code was the best core measure of the 70’s Most applications have operators, not users Coded lines of code Limited number of languages (COBOL, Assembler) within organization Mind set was “code driven” Function Points Function Points is the best core measure of the 90’s and beyond User focus Paint an application (copy, click, drag, drop), some coding with heavy reuse Dozens of languages and technologies in most organizations Mind set is “functionality & value driven”

10. 10 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. A Function Point Count is Established Based on Functional Requirements Function TypesExample Count Data Functions Internal Logical Files- Empl. Files (3) - 45 FPs - Trans. Files (3) - 30 FPs External Interface Files- Password Files - 5 FPs - HRM Data Base - 5 FPs Transactional Functions External Inputs- Timesheet Trans. - 3 FPs - Deductions - 4 FPs External Outputs- P/R Report - 4 FPs - Checks - 7 FPs External Inquiry- N&A Inquiry - 3 FPs - Check Register - 6 FPs TOTAL = 112 Function Points

11. 11 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Step 2. Evaluation of Project Attributes Technical Environment Platform - Mainframe, PC, C/S etc Software Use - Internal, Commercial, Government etc Development Method - Traditional, OOD, Web etc. Development Type - New Development, Enhancement Project Characteristics Personnel and Management Process and Methods Technology and Tools Environment and Support

12. 12 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Productivity rates will vary by Technical Environment –PC higher productivity vs. C/S lower productivity –New development higher than enhancement Project Characteristics have a significant impact on productivity and quality –Make-up of project team –Adequacy of processes and tools –Project constraints and requirements Assess project risk Continuous process improvement –Identify new opportunities –Measure the impact of new initiatives Why Evaluate Project Attributes?

13. 13 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Project Characteristics Impact % Impact on Project Project AttributesEffort and Schedule Personnel Management+/-100% Process and Methods+/-75% Technology and Tools+/-50% Environment and Support+/-25%

14. 14 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Project Characteristics - Adjustment Factor Example ScoreWeighted Project Score Influence Personnel Management1-Low1.5 I/S Personnel Knowledge and Experience21.25 1.25 User Personnel Knowledge and Experience3-Avg.1 Personnel Management and Support40.83 5-High0.75 Process and Methods1-Low1.38 Development Methods and Techniques21.19 Project Management Methods and Tech3-Avg1 Q/A and Control Methods and Tech40.89.89 Measurement Methods and Techniques5-High0.72 Multiply the weighted scores together. This is your effort and schedule Adjustment Factor 1.11

15. 15 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Customization / Calibration Project Attributes You can customize the Attribute influences to reflect your own particular environment An advantage of this technique is that you can identify the influencing ratio you feel are appropriate. By weighting these influencing factors the estimates can become more reliable and accurate. Adjustments should be based on an analysis of past projects and their influencing factors

16. 16 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Step 3. Establish Productivity Rating FP/Hour Project Function Point Size Productivity rates vary by size - analyze your past performance Enhancement Project Productivity

17. 17 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Productivity Rates are Established based on Historical Data and/or External Benchmarks Project History Database - Client Server New Development SizeEffortP-RateSchedule Benchmark by Size Category (FPs)Months FP/Mo.Months FP Range P-Rate Schedule 1006172 1107163 1156193 1509173 100-15017 FP/Mo 2.75 Mo. 16010164 17012144 17516115 1765356 151-20016 FP/Mo 4.75 Mo. 25520137 26225108 2703099 27435810 27936811 201-3009 FP/Mo 9.00 Mo. 30542712 40648810 48065713 301-4008 FP/Mo 12.00 Mo.

18. 18 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. External Benchmark Data is Available (Public and Proprietary) Major Considerations for Evaluating Benchmark Data What is the size of the database? How current is the data? What types of organizations are represented? (sector, size, technology, maturity, geography) How consistent and accurate is the information? –Time accounting and cost standards –Function points vs. Line of Code size –Defect definition and timing

19. 19 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Step 4: Develop Estimate Function Point Estimate Project X – 112 FPs Historical Rates Effort = 6.5 Months Schedule Duration = 2.75 Months Productivity =17 FPs/Mo. Project Attributes Client Server New Development Below Average Personnel Management Above Average Process and Methods Project Characteristics Adjustment Factor = 1.11 Project Estimate Based on Standard Rates from Historical Data Effort = 6.5 months Schedule = 2.75 months Productivity Rate = 17 FP/Mo. Project Estimate Based on Adjusted Rates Effort = 7.2 months Schedule = 3.05 months Productivity Rate = 15 FP/Mo.

20. 20 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Calibration and Refinement Must define your terms carefully, and recognize what is most susceptible to inconsistent reporting of measures. Where necessary adjust (calibrate) the estimate to conform with the project situation. Define the Chart of Accounts Estimate by Phase/Activity as appropriate Carefully define cost components Consider reuse Consider scope creep and requirement clarity Adjust for schedule compression

21. 21 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Scope Creep - A Special Consideration As projects progress, new requirements not considered previously become identified, this is known as “scope creep”. On average projects encounter scope creep of approximately 35% from requirements definition to implementation. Small project (<100FPs) 5-15% Large projects (>1500FPs) 50-200% By using techniques such as a clarity of requirements risk assessment while conducting a function point count, scope creep can be anticipated more accurately.

22. 22 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Other Considerations for Estimating Overstaffing may reduce schedule duration but will always increase effort and cost Accuracy improves with detail Use a number of estimating techniques for improved accuracy Do not underestimate the impact of project size on productivity rates –Complexity –Management overhead Cost is derivative of effort plus travel, hardware, software, training, miscellaneous Consider trade-offs between staff size and schedule duration Use ranges to communicate estimates

23. 23 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Documenting the Estimate Purpose of the estimate Identify the estimates Identify the level of accuracy of the estimate Identify the assumptions and interpretations Identify the techniques and approaches used Identify the estimation models used Identify the trigger for the next estimate

24. 24 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Communication - The Estimate Report Table of Contents Project Background and Description Sponsor and Participant Information Project Scope Estimation Methodology Project Constraints Project Assumptions Function Point Analysis Attribute Evaluation Estimate Issues and Recommendations Summary

25. 25 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Summary Estimating is primarily a communications process Understanding and communicating assumptions is key Size has the greatest impact on effort and schedule Function points are the best measure of size Estimating improves with experience Estimates are only as accurate as the requirements Historical data greatly improves estimating accuracy Calibration is required for greater accuracy

26. 26 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Estimation with Functional Metrics Benefits Identify and quantify size based on the customers perspective Estimate early in the development process Quantify and manage change of scope Base agreements on measured data Monitor progress compared to estimates Recognize requirements problems early and take corrective action Improve communications Repeatable

27. 27 © Copyright 2000-2001. Q/P Management Group, Inc. All Rights Reserved. Getting Started Get educated on using functional metrics as an estimating and management tool - spread the word Get trained in detailed Function Point Analysis or utilize external expertise Look for opportunities to apply function points (pilot) –Defining requirements –Estimating projects –Evaluating COTS and vendors Establish a measurement repository –Historical project performance statistics –External benchmark data Establish an ongoing process –Integrate with life cycle and organizational activities –Develop expertise