Comparison and Renaissance of Classic Line-of-Balance and Linear Schedule Concepts for Construction Industry

Abstract

Line-of-Balance (LOB) is a useful analytical tool for repetitive activities in construction projects, which allows showing which crew is assigned to what repetitive work unit of an activity. LOB is closely related to the linear scheduling method, but possesses some challenges: It must be clarified how it counts, as previous studies displayed an apparent measurement gap at the origin, implicitly representing that LOB starts at the first unit finish. Slopes in linear scheduling and LOB are different, even though both portray a measure of progress of an activity. This paper therefore tracks evolution and current use of LOB versus linear schedules. Its contribution to the body of knowledge is threefold: First, based on a literature review, LOB is found to be rooted in Activity-on-Arrow (AOA) diagrams, which makes it event-centered, not progresscentered. Differences in representing the start and productivity between LOB and linear scheduling are reviewed and explained both mathematically and graphically. Second, different LOB concepts are extracted and assessed to facilitate comparing LOB from its original use in manufacturing against the limited application of its objective chart in the construction industry. Third, a mathematical formulation based on singularity functions is developed, which can model staggering, continuity, and interruptability scenarios. Fourth, the repetitive nature of LOB and LSM enables resource-specific equations that model the level of detail of individual crews performing individual tasks.

Comparing Production Design Activities and Location-Based Planning Tools

“…In relation to the lines/boxes slope, Su and Lucko (2015) point out that the line of balance presents the delivery rate, whilst the flowline shows the production rate. The difference between them are: the delivery rate starts counting after the first unit completion, whilst the production rate starts counting from the beginning of activity execution (Su and Lucko 2015).…”

“…The difference between them are: the delivery rate starts counting after the first unit completion, whilst the production rate starts counting from the beginning of activity execution (Su and Lucko 2015). In TTP, the boxes slope represents the takt-time, or customer demand rate, or phase demand rate when applied in the phase scheduling.…”

Method for Base Estimation of Construction Time for Linear Projects in Front-end Project Phases

“…There are numerous linear scheduling techniques based on the time-location diagram, in which one axis represents the time and the other represents the location ( Figure 2). The two most known linear scheduling methods are the "line of balance (LOB)" method and the LSM (Su and Lucko, 2015). These two methods both use the coordinate system of work and time, but fundamental differences exist in activity representation, project start, and productivity between the LOB and LSM models Lucko, 2015, 2016).…”

Software for Line of Balance in Projects of Highways

“…Line of Balance (LOB) can be considered as the most effective technique for presentation of linear construction projects with receptive activities such as highway works [14]. In contrast with network methods, planning based on Line of Balance (LOB) technique can be considered as the most appropriate technique for highway construction projects as they involve repetitive environment [14][15][16].…”

“…Line of Balance (LOB) can be considered as the most effective technique for presentation of linear construction projects with receptive activities such as highway works [14]. In contrast with network methods, planning based on Line of Balance (LOB) technique can be considered as the most appropriate technique for highway construction projects as they involve repetitive environment [14][15][16]. In spite of the advantages of LOB technique on other scheduling methods such as bar charts and critical path method (CPM) [17][18][19], its use is still limited [20] in comparison with the use of computerized packages of CPM due to their availability and simplicity [10].…”