- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 24 Feb 2017
Line of balance (LOB)
Line of balance (LOB) is a management control process used in construction where the project contains blocks of repetitive work activities, such as roads, pipelines, tunnels, railways and high-rise buildings. LOB collects, measures and presents information relating to time, cost and completion, and presents it against a specific plan.
LOB assists project management by:
- Comparing a formal objective against actual progress.
- Examining the extent of any deviations from specific plans, in terms of knock-on effects.
- Identifying in advance problematic areas where corrective action may be required.
- Forecasting future performance.
The LOB technique was created by the Goodyear Company in the early 1940s, before being adopted and developed by the U.S. Navy in the early-1950s. It was subsequently developed for industrial manufacturing and production control, as well as the basic concepts behind planning and scheduling in the construction industry.
An LOB diagram shows the repetitive project work as a single line on a graph. It differs from a bar chart which shows a particular activity’s duration, by showing the rate at which the work has to be undertaken to stay on schedule, as well as the relationship of one trade or process to the subsequent trade or process.
The project timeline is represented along the x-axis of the LOB diagram. The work areas that define the project are represented along the y-axis. This is the starting point for the LOB schedule:
As Activity B continues, at the end of the week 4 work can begin on the second floor; at the end of week 6 work can begin on the third floor, and so on. The horizontal red dashed lines represent the breaks in Activity B work, where the workforce is waiting for Activity A to clear the way for them to continue. In this example, starting Activity B as soon as possible will result in a lost productivity of 4 weeks.
The diagram below shows that by delaying the start of Activity B for 4 weeks, the workforce can continue uninterrupted, and hence are more productive. This enables a better understanding of how workforces follow one another through activities.
The advantages of LOB include:
- Allowing a clearer understanding of the amount of work taking place at a certain time in a specific place.
- Resources can be optimised for a large number of repeated work activities.
- As all information is available for each activity, it allows easier cost and time optimisation analysis.
- It is relatively easy to modify, update and change the schedule.
- It allows better management of subcontractors and resources.
- It allows problem areas to be identified in advance.
 Related articles on Designing Buildings Wiki
- Activity schedule.
- Advanced manufacturing.
- Block planning.
- Clash avoidance.
- Critical path method.
- Design coordination.
- Gantt chart.
- Key dates.
- Logistics management.
- Pareto analysis.
- Programme for building design and construction.
- Project manager.
- Resource leveling.
- Scheduling construction activities.
- Time-location chart.
- Time management of construction projects.
 External resources
- CPM Tutor - Line of balance
Featured articles and news
The quality of Cambridge owes as much to its open spaces as to its architectural uniqueness.
If events occur that cause the completion of the works to be delayed then these may be compensation events.
BSRIA's new Building MOTs Scheme is designed to provide guidance on the next steps after compliance.
At an ICE discussion, the focus was on delivering a Northern Infrastructure Strategy based on opportunity for all.
The Considerate Constructors Scheme officially launch the new Ultra Site status for contractors and supply chains.
The risk of specification errors in the cladding sector is "worryingly high" after Grenfell, according to major distributor.
Here is our outline work plan for a private sector design and build project.
BRE are to publish new guidance aimed at assuring buyers as to the merits of off-site construction methods.
Who are the various different stakeholders in development projects? Find out in our introductory article.
How a BRE office became the centre-piece for major biophilic design research.