Mill Clocks and Earned Schedule



By Crispin “Kik” Piney

South of France


The historical information is based on the Princeton University Department of History course “Technologies and Their Societies: Historical Perspectives” by Professor Michael S. Mahoney.


In the same way as for the early industrialization of work and formalization of labour, project management aims to make most effective and profitable use of planning and resource capabilities. As David S. Landes, states in “The Unbound Prometheus”, “The factory was more than just a larger work unit.  It was a system of production resting on a characteristic definition of the functions and responsibilities of the different participants in the productive process.” That sentence could as easily describe the modern project environment.

This note takes lessons from the early days of the industrial revolution and applies them to project management.

Mill Clocks and Progress Tracking

The factory was considered as a machine, composed of individual entities acting together as parts of a larger, continuously operating mechanism with a central power source (whether water or steam) driving all machines at coordinated rates. This can be compared to the various project components that need to be coordinated and executed in accordance with a formal plan.

Some mills had a specially-devised mill clock that provided both pacing of the work and tracking of progress with respect to the plan: “Many mills have a clock turned by the mill; close to another clock regulated by a pendulum. Both are made with dials and hands exactly alike, but one has a title on the dial ‘mill time’, and the other, ‘clock time’.” (The Rees Cyclopedia). An image of one such installation is shown in Figure 1.

Figure 1: Analogue Earned Schedule. The clock on the left measures the current time; the one on the right corresponds to work completed.

Being driven by the power source based on the rate of the work, the hands of the mill clock therefore moved according to the amount of work carried out, whereas those of the pendulum clock measured the passing of time. The gearing of the mill clock was set to correspond to the work rate specified by the management. For an actual work rate in line with this target, the time on the mill clock would always agree with the clock time. Work therefore earned time on the mill clock, and this had to keep pace with the time shown on the pendulum clock. In a well-regulated mill, these two clocks would never vary by more than a few minutes. In the image shown in Figure 1, the mill clock (on the right) is almost one hour behind the time shown on the pendulum clock (on the left). This corresponds to a work rate that is lagging significantly behind the target set by management.


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How to cite this article: Piney, C. (2022).  Mill Clocks and Earned Schedule, commentary, PM World Journal, Vol. XI, Issue XI, November.  Available online at https://pmworldlibrary.net/wp-content/uploads/2022/11/pmwj123-Nov2022-Piney-mill-clocks-and-earned-schedule.pdf

About the Author

Crispin “Kik” Piney



After many years of managing international IT projects within large corporations, Crispin (“Kik”) Piney, B.Sc., PgMP is now a freelance project management consultant based in the South of France. At present, his main areas of focus are risk management, integrated Portfolio, Program and Project management, scope management and organizational maturity, as well as time and cost control. He has developed advanced training courses on these topics, which he delivers in English and in French to international audiences from various industries. In the consultancy area, he has developed and delivered a practical project management maturity analysis and action-planning consultancy package.

Kik has carried out work for PMI on the first Edition of the Organizational Project Management Maturity Model (OPM3™) as well as participating actively in fourth edition of the Guide to the Project Management Body of Knowledge and was also vice-chairman of the Translation Verification Committee for the Third Edition. He was a significant contributor to the second edition of both PMI’s Standard for Program Management as well as the Standard for Portfolio Management. In 2008, he was the first person in France to receive PMI’s PgMP® credential; he was also the first recipient in France of the PfMP® credential. He is co-author of PMI’s Practice Standard for Risk Management. He collaborates with David Hillson (the “Risk Doctor”) by translating his monthly risk briefings into French. He has presented at a number of recent PMI conferences and published formal papers.

Kik Piney is the author of the book Earned Benefit Program Management, Aligning, Realizing and Sustaining Strategy, published by CRC Press in 2018

Kik Piney can be contacted at kik@project-benefits.com.

To view other works by Kik Piney, visit his author showcase in the PM World Library at http://pmworldlibrary.net/authors/crispin-kik-piney/