Just-in-Time Line of Balance



By Dr. Ken Smith

Honolulu, Hawaii



JITLOB is an enhancement to the Critical Path Method (CPM), using Cumulative critical path analysis in conjunction with Line of Balance (LOB)[1] a traditional production-line planning technique — to improve scheduling & monitoring of repetitive-type projects and processes.

The Critical Path Method has been recognized since the early 1960’s as the “Best Practice” technique to plan, schedule, monitor and manage complex “one-off” Projects — i.e. where only one pass through the network completes the project.  But the acclaim and subsequent clamor for Critical Path almost completely eclipsed awareness and application of the Line of Balance technique for managing repetitive-type projects & processes — even though LOB preceded CPM by almost 20 years

LOB continues to be used in some infrastructure applications, but the international Project Management Institute (PMI)® has ignored it — perhaps because manufacturing terminologyLine of Balance fails to convey the core concept of ‘Just-in-Time’ scheduling it embraces.  Consequently, most PMPs and other personnel schooled by PMI’s “PMBOK©” have never been exposed to LOB technology; so succeeding generations of Project Managers in sectors other than construction are completely unaware of it.

Nevertheless — despite being overshadowed and rendered dormant by CPM’s advent — LOB is a Much Better Practice[2] for planning & monitoring repetitive-type projects than now-conventional critical path methods, as it can significantly reduce overall project durations & costs.[3]

Furthermore, most sectors have projects or component processes that are totally or partially repetitive in nature, so the possibilities for deriving such scheduling and cost benefits with sub-optimal LOB applications are widespread.

Therefore, although this presentation is not ‘timely,’ hopefully re-designated as “JITLOB”[4] and disseminated de novo as an enhanced Critical Path application, awareness of LOB concepts within today’s project management community will be heightened, and its use in scheduling, monitoring & managing repetitive-type projects & processes will increase commensurately with the generic template illustrated herein

Here then — Better Late than Never — is “Just in Time Line of Balance” (JITLOB)


During planning “one-off”-type projects, their activities and milestones are identified, and bounded by Start and Completion Milestones, and their sequential interrelationships & duration are further refined.  Once this has been accomplished, the key series of activities that determine how long it is likely to take before the entire project can be completed is designated the ‘critical path.  The project’s sponsor may then accept this ‘technical/engineered’ estimate, or alternately impose a different ¾ often a tighter ¾ deadline (or target) for the Project Manager to attain.  The planners then reexamine the project, focusing on critical path activities and weighing alternatives for completing the project by the deadli


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How to cite this article: Smith, K. F. (2020).  Just-in-Time Line of Balance, PM World Journal, Vol. IX, Issue X, October.  Available online at https://pmworldlibrary.net/wp-content/uploads/2020/10/pmwj98-Oct2020-Smith-just-in-time-line-of-balance.pdf



About the Author

Dr. Kenneth Smith

Honolulu, Hawaii


Dr. Kenneth F. Smith was a project management consultant for ADB, the World Bank, and USAID for decades. He earned his DPA (Doctor of Public Administration) from the George Mason University (GMU) in Virginia and his MS from Massachusetts Institute of Technology (MIT Systems Analysis Fellow, Center for Advanced Engineering Study). A long-time member of the Project Management Institute (PMI) and IPMA-USA, Dr. Smith is a Certified Project Management Professional (PMP®) and a member of the PMI®-Honolulu Chapter.

Ken’s book — Project Management PRAXIS (available from Amazon) — includes many other innovative project management tools & techniques; and describes a “Toolkit” of related templates available directly from him at kenfsmith@aol.com.


[1] Line of Balance (LOB) was conceived by George Fouch, General Manager of the Goodyear Aircraft Corporation in 1942 to optimize mass production scheduling of World War II war materiel for the US Navy.  LOB was subsequently adopted by the US Defense Department in 1947 and applied extensively to military logistics management when Fouch was appointed Deputy Assistant Secretary of Defense for installations & logistics

[2] In 1961, as a US Navy Management Intern with the Bureau of Weapons, I learned LOB from Art Gehringer, and CPM from mentor Tom Ensor of the Special Projects Office; then applied them on-the-job – along with other techniques — through 1963 as a management analyst in the Navy Management Office (NMO).  Subsequently — for two years (1964 & 1965) under the direction of Guy Best — as a management systems specialist & faculty member cum consultant of the interagency Pert Orientation & Training Center (POTC), I fostered the use of CPM & LOB throughout the US government, as ‘Best’s Practices.’  Since then, I have applied both techniques on numerous projects in different sectors — as well as taught them — world-wide, for various international development agencies and PMI® chapters.

[3] For example, an eleven-week process consisting of three activities — 2, 6, and 3 weeks respectively — would take 55 weeks, if repeated sequentially five times.  But optimally ‘balanced’ as eleven one-week activities, the process could be completed in only 15 weeks!  Even sub-optimized LOB scheduling i.e. retaining the sequence ‘as is’ — would accelerate the process to 35 weeks; still a significant 36% percent schedule improvement over sequential processing; as well as 20 weeks of savings in indirect costs!

[4] Rather than simply supplanting and pretentiously ‘reinventing’ it, ‘Line of Balance’ retains George Fouch’s antecedent designation for his manufacturing planning technique and its subsequent adaptation for infrastructure projects.  The ‘Just-in-Time’ prefix in this update connotes a reverse-scheduled Cumulative Critical Path concept, to highlight LOB’s relevance to planning & scheduling other types of Projects of the Repetitive kind.