Learning, Unlearning and Re-learning Curves (Volume IV of the Working Guides to Estimating & Forecasting series) focuses in on Learning Curves, and the various tried and tested models of Wright, Crawford, DeJong, Towill-Bevis and others. It explores the differences and similarities between the various models and examines the key properties that Estimators and Forecasters can exploit.
A discussion about Learning Curve Cost Drivers leads to the consideration of a little used but very powerful technique of Learning Curve modelling called Segmentation, which looks at an organisation’s complex learning curve as the product of multiple shallower learning curves. Perhaps the biggest benefit is that it simplifies the calculations in Microsoft Excel where there is a change in the rate of learning observed or expected. The same technique can be used to model and calibrate discontinuities in the learning process that result in setbacks and uplifts in time or cost. This technique is compared with other, better known techniques such as Anderlohr’s.
Equivalent Unit Learning is another, relative new technique that can be used alongside traditional completed unit learning to give an early warning of changes in the rates of learning. Finally, a Learning Curve can be exploited to estimate the penalty of collaborative working across multiple partners. Supported by a wealth of figures and tables, this is a valuable resource for estimators, engineers, accountants, project risk specialists, as well as students of cost engineering.
"In the Working Guides to Estimating and Forecasting Alan has managed to capture the full spectrum of relevant topics with simple explanations, practical examples and academic rigor, while injecting humour into the narrative." Dale Shermon, Chairman, Society of Cost Analysis and Forecasting (SCAF).
"If estimating has always baffled you, this innovative well illustrated and user friendly book will prove a revelation to its mysteries. To confidently forecast, minimise risk and reduce uncertainty we need full disclosure into the science and art of estimating. Thankfully, and at long last the "Working Guides to Estimating & Forecasting" are exactly that, full of practical examples giving clarity, understanding and validity to the techniques. These are comprehensive step by step guides in understanding the principles of estimating using experientially based models to analyse the most appropriate, repeatable, transparent and credible outcomes. Each of the five volumes affords a valuable tool for both corporate reference and an outstanding practical resource for the teaching and training of this elusive and complex subject. I wish I had access to such a thorough reference when I started in this discipline over 15 years ago, I am looking forward to adding this to my library and using it with my team." - Tracey L Clavell, Head of Estimating & Pricing, BAE Systems Australia
"At last, a comprehensive compendium on these engineering math subjects, essential to both the new and established "cost engineer"! As expected the subjects are presented with the author’s usual wit and humour on complex and daunting "mathematically challenging" subjects. As a professional trainer within the MOD Cost Engineering community trying to embed this into my students, I will be recommending this series of books as essential bedtime reading." - Steve Baker, Senior Cost Engineer, DE&S MOD
"Alan has been a highly regarded member of the Cost Estimating and forecasting profession for several years. He is well known for an ability to reduce difficult topics and cost estimating methods down to something that is easily digested. As a master of this communication he would most often be found providing training across the cost estimating and forecasting tools and at all levels of expertise. With this 5-volume set, Working Guides to Estimating and Forecasting, Alan has brought his normal verbal training method into a written form. Within their covers Alan steers away from the usual dry academic script into establishing an almost 1:1 relationship with the reader. For my money a recommendable read for all levels of the Cost Estimating and forecasting profession and those who simply want to understand what is in the ‘blackbox’ just a bit more." - Prof Robert Mills, Margin Engineering, Birmingham City University. MACOSTE, SCAF, ICEAA.
"Finally, a book to fill the gap in cost estimating and forecasting! Although other publications exist in this field, they tend to be light on detail whilst also failing to cover many of the essential aspects of estimating and forecasting. Jones covers all this and more from both a theoretical and practical point of view, regularly drawing on his considerable experience in the defence industry to provide many practical examples to support his comments. Heavily illustrated throughout, and often presented in a humorous fashion, this is a must read for those who want to understand the importance of cost estimating within the broader field of project management." - Dr Paul Blackwell, Lecturer in Management of Projects, The University of Manchester, UK.
"Alan Jones provides a useful guidebook and navigation aid for those entering the field of estimating as well as an overview for more experienced practitioners. His humorous asides supplement a thorough explanation of techniques to liven up and illuminate an area which has little attention in the literature, yet is the basis of robust project planning and successful delivery. Alan’s talent for explaining the complicated science and art of estimating in practical terms is testament to his knowledge of the subject and to his experience in teaching and training." - Therese Lawlor-Wright, Principal Lecturer in Project Management at the University of Cumbria
"Alan Jones has created an in depth guide to estimating and forecasting that I have not seen historically. Anyone wishing to improve their awareness in this field should read this and learn from the best." Richard Robinson, Technical Principal for Estimating, Mott MacDonald
"The book series of ‘Working Guides to Estimating and Forecasting’ is an essential read for students, academics and practitioners who interested in developing a good understanding of cost estimating and forecasting from real-life perspectives". Professor Essam Shehab, Professor of Digital Manufacturing and Head of Cost Engineering, Cranfield University, UK.
"In creating the Working Guides to Estimating and Forecasting, Alan has captured the core approaches and techniques required to deliver robust and reliable estimates in a single series. Some of the concepts can be challenging, however, Alan has delivered them to the reader in a very accessible way that supports lifelong learning. Whether you are an apprentice, academic or a seasoned professional, these working guides will enhance your ability to understand the alternative approaches to generating a well-executed, defensible estimate, increasing your ability to support competitive advantage in your organisation." - Professor Andrew Langridge, Royal Academy of Engineering Visiting Professor in Whole Life Cost Engineering and Cost Data Management, University of Bath, UK.
"Alan Jones’s "Working Guides to Estimating and Forecasting" provides an excellent guide for all levels of cost estimators from the new to the highly experienced. Not only does he cover the underpinning good practice for the field, his books will take you on a journey from cost estimating basics through to how estimating should be used in manufacturing the future – reflecting on a whole life cycle approach. He has written a must-read book for anyone starting cost estimating as well as for those who have been doing estimates for years. Read this book and learn from one of the best." - Linda Newnes, Professor of Cost Engineering, University of Bath, UK.
Volume IV Table of Contents, 1 Introduction and Objectives, 1.1 Why write this book? Who might find it useful? Why Five Volumes?, 1.1.1 Why write this series? Who might find it useful?, 1.1.2 Why Five Volumes?, 1.2 Features you'll find in this book and others in this series, 1.2.1 Chapter Context, 1.2.2 The Lighter Side (humour), 1.2.3 Quotations, 1.2.4 Definitions, 1.2.5 Discussions and Explanations with a Mathematical Slant for Formula-philes, 1.2.6 Discussions and Explanations without a Mathematical Slant for Formula-phobes, 1.2.7 Caveat Augur, 1.2.8 Worked Examples, 1.2.9 Useful Microsoft Excel Functions and Facilities, 1.2.10 References to Authoritative Sources, 1.2.11 Chapter Reviews, 1.3 Overview of Chapters in this Volume, 1.4 Elsewhere in the 'Working Guide to Estimating & Forecasting' Series, 1.4.1 Volume I: Principles, Process and Practice of Professional Number Juggling, 1.4.2 Volume II: Probability, Statistics and other Frightening Stuff, 1.4.3 Volume III: Best Fit Lines & Curves, and some Mathe-Magical Transformations, 1.4.4 Volume IV: Learning, Unlearning and Re-Learning Curves, 1.4.5 Volume V: Risk, Opportunity, Uncertainty and Other Random Models, 1.5 Final Thoughts and Musings on this Volume and Series, References, , 2 Quantity-based Learning Curves, 2.1 A Brief History of the Learning Curve as a Formal Relationship, 2.2 Two Basic Learning Curve Models (Wright and Crawford), 2.2.1 Wright Cumulative Average Learning Curve, 2.2.2 Crawford Unit Learning Curve, 2.2.3 Wright and Crawford Learning Curves Compared, 2.2.4 What's So Special about the Doubling Rule?, 2.2.5 Learning Curve Regression - What appears to be Wright, may in fact be Wrong!, 2.3 Variations on the Basic Learning Curve Models, 2.3.1 DeJong Unit Learning Curve, 2.3.2 DeJong-Wright Cumulative Average Hybrid Learning Curve, 2.3.3 Stanford-B Unit Learning Curve, 2.3.4 Stanford-Wright Cumulative Average Hybrid Learning Curve, 2.3.5 S-Curve Unit Learning Curve, 2.3.6 S-Curve-Wright Cumulative Average Hybrid Learning Curve, 2.4 Where and When to Apply Learning and How Much?, 2.4.1 To What Kind of Task can a Learning Curve be applied?, 2.4.2 Additive and Non-Additive Properties of Learning Curves, 2.4.3 Calibrating or Measuring Observed Learning, 2.4.4 What if we don't have any actuals? Rules of Thumb Rates of Learning, 2.5 Changing the Rate of Learning - Breakpoints, 2.5.1 Dealing with a Breakpoint in a Unit Learning Curve Calculation, 2.5.2 Dealing with a Breakpoint in a Cumulative Average Learning Curve Calculation, 2.6 Learning Curves: Stepping Up and Stepping Down, 2.6.1 Step-points in a Unit Learning Curve Calculation, 2.6.2 Step-points in a Cumulative Average Learning Curve Calculation, 2.7 Cumulative Values of Crawford Unit Learning Curves, 2.7.1 Conway-Schultz Cumulative Approximation, 2.7.2 Jones Cumulative Approximation, 2.7.3 Cumulative Approximation Formulae Compared, 2.7.4 Batch or Lot Averages, 2.7.5 Profiling Recurring Hours or Costs - the Quick Way, 2.8 Chapter Review, References, , 3 Unit Learning Curve - Cost Driver Segmentation, 3.1 Learning Curve Cost Driver Studies - What Others Have Said, 3.1.1 Loud and Clear, 3.1.2 Jefferson's Pie, 3.2 Cost Driver Changes and Breakpoints, 3.2.1 Output Rate: Driver or Consequence of Learning?, 3.2.2 End-of-Line Effects on Learning, 3.3 Segmentation Approach to Unit Learning, 3.3.1 Stopping and Starting from Where We Left Off, 3.3.2 What If We Invest More or Less Up-front?, 3.3.3 Rate Affected Learning Revisited, 3.3.4 Parallel v Serial Working, 3.3.5 Calibrating the Cost Driver Segment Contributions, 3.4 Chapter Review, References, , 4 Unlearning and Re-Learning Techniques, 4.1 Reasons to Forget, 4.2 Anderlohr's Technique, 4.3 An Alternative Simplified Retrograde Technique (Not Recommended), 4.4 Segmentation Technique, 4.5 Comparison of Re-Learning Techniques, 4.6 Calibrating the Level of Learning Lost, 4.6.1 Calibrating the Level of Learning Lost Using the Segmentation Technique, 4.6.2 Calibrating the Level of Learning Lost Using the Anderlohr Technique, 4.7 Chapter Review, References, , 5 Equivalent Unit Learning, 5.1 The Problems with Traditional Unit Learning Curves, 5.2 Development of the Equivalent Unit Learning Theory, 5.2.1 EUL Confidence and Prediction Intervals, 5.3 Equivalent Unit Learning and Breakpoints, 5.4 Double-Bunking Data for Early Debunking of Breakpoints, 5.5 Equivalent Unit Learning and Achievement Mortgaging (Progress Optimism Bias), 5.6 Using Equivalent Unit Learning as a Top-down Validation, 5.7 Benefits of Using Equivalent Unit Learning, 5.8 Chapter Review, References, , 6 Multi-Variant Learning, 6.1 Multi-Variant Learning Curves, 6.1.1 Option 1: Ignore Differences (ID), 6.1.2 Option 2: Fixed Factors (FF), 6.1.3 Option 3: Total Separation (TS), 6.1.4 Option 4: Proportional Representation (PR), 6.2 Multi-Variant Learning Curve Model Calibration, 6.2.1 Calibration with the ID Approach, 6.2.2 Calibration with the FF Approach, 6.2.3 Calibration with the TS Approach, 6.2.4 Calibration with the PR Approach, 6.2.5 Comparison of Results, 6.3 Cross-Product Organisational Learning Curve Models, 6.4 Chapter Review, References, 7 Time-Based Learning Curves, 7.1 Time-Performance Learning Curve, 7.2 Bevis-Towill Time-Constant Model, 7.3 Cross-Product Organisational Learning Curve Models Revisited, 7.4 Chapter Review, References, 8 The Cost Impact of Collaborative Working, 8.1 Collaborative Development Costs with Equal Workshare Partners, 8.2 The Collaborative Development with Unequal Workshare Partners, 8.3 Production Cost Implications of Collaborative Working, 8.4 Chapter Review, References, Glossary of Estimating Terms
As engineering and construction projects get bigger, more ambitious and increasingly complex, the ability of organizations to work with realistic estimates of cost, risk or schedule has become fundamental.
And working with estimates requires technical and mathematical skills from the estimator but it also requires an understanding of the processes, the constraints, and the context by those making investment and planning decisions. You can only forecast the future with confidence if you understand the limitations of your forecast.
The Working Guides to Estimating introduce, explain and illustrate the variety and breadth of numerical techniques and models that are commonly used to build estimates. Alan Jones defines the formulae that underpin many of the techniques; offers justification and explanations, for those whose job it is to interpret the estimates; advice on pitfalls and shortcomings and worked examples. These are often tabular in form to allow you to reproduce the examples in Microsoft Excel. Graphical or pictorial figures are also frequently used to draw attention to particular points as the author advocates that you should always draw a picture before and after analysing data.
The five volumes in the Series provide expert applied advice for estimators, engineers, accountants, project risk specialists as well as students of cost engineering, based on the author’s thirty-something years’ experience as an estimator, project planner and controller.
This complimentary eResource is provided to assist users of the Working Guides to Estimating and Forecasting series of books in recreating the tables and figures from the published books (printed or electronic). It is supplementary to, and is not intended to replace, the material in the published books. The files are available to download in their original colour format.
This material is copyrighted by the author and is provided solely as an aid to learning. Neither the author nor the publisher accepts any liability for its subsequent use or adaptation for any other purpose other than for which it was originally intended.
The figures and tables are provided in either interactive Microsoft Excel spreadsheet files, complete in general with the original calculation formulae, or as static images, where the reader may prefer to view those examples in full colour that were created in Microsoft PowerPoint. Any tables originally created in Microsoft Word have been converted and included in the Microsoft Excel files to reduce the number of download options for the users.
CAVEAT AUGUR: Whilst the author considers it to be good practice to lock calculation cells etc and to protect worksheets and workbooks, this has not been done here; the spreadsheets have been left unlocked and unprotected. Neither have the worksheet examples been independently Validated and Verified, as is also good practice.