Line-of-balance against linear scheduling: critical comparison

Abstract

Among alternative scheduling techniques in construction management are linear and repetitive scheduling and line of balance (LOB). They are uniquely different from the dominant network-based technique because they have been developed for projects with repetitive units of work and crew operations. Notably, they feature quantitative measures of both work and time, which no network-based approach offers. However, a study of their origins – for example, the US Navy – reveals that their original use and capabilities deviate from current application, which is limited at best. Indeed, currently, the name-giving LOB is itself omitted. Therefore, this research has the goal to explore these scheduling techniques in detail. Its objectives are to delineate their modelling elements as described by original sources in a structured manner, to compare them in detail and identify any changes over time and to comment on implications for practical use and extract unsolved research questions. Its methodology follows a comparative research approach. Differences are found in how productivity and cyclic crew deployment are expressed, besides the glaring omission of the LOB itself in the construction use of this method. It is found that, historically, LOB was intended for manufacturing, but when introduced to construction, important characteristics of the production plan and progress chart became forgotten. In parallel, linear scheduling was developed for construction, whose similarities to LOB may have added confusion. Clarifying the complete methods by explicitly outlining their analytical capabilities will improve understanding to allow project managers to benefit from these powerful tools. It also enables future research to model LOB with singularity functions to yield a unified formulation of these alternative scheduling techniques.