Line of Balance Technique: Managing Repetitive Projects Efficiently

Managing a project with dozens of identical or near-identical tasks – think planting cycles across multiple fields, processing batches on a food production line, or assembling units in an agri-equipment plant – is far more complex than it looks on a simple to-do list. Tasks overlap, teams interfere with each other, resources get stretched thin, and delays in one stage silently disrupt everything downstream. Traditional bar charts and Gantt charts can capture individual activity durations, but they struggle to show whether your entire operation is moving at the right pace. That’s exactly the problem the Line of Balance (LOB) technique was built to solve.

What is the line of balance technique? 🔗

Line of Balance is a management control process for collecting, measuring, and presenting facts relating to time, cost, and accomplishment – all measured against a specific plan. At its core, it is a graphical scheduling tool that plots repetitive project activities as lines on a chart, allowing managers to see at a glance whether every activity is proceeding at the pace required to meet delivery targets. Rather than asking “how long does this task take?”, LOB asks a more operationally powerful question: “are we producing at a pace that allows an even, uninterrupted flow through the entire process?”

According to Designing Buildings, the LOB technique was first created by the Goodyear Company in the early 1940s and was later adopted and further developed by the U.S. Navy in the early 1950s for programming and controlling both repetitive and non-repetitive projects. It subsequently found wide application in industrial manufacturing and production control, and its core concepts have since been adopted as a planning and scheduling method in the construction industry and beyond. Today, it is also known by several other names: the Repetitive Scheduling Method (RSM), Location-Based Scheduling, Vertical Production Method, or Vertical Scheduling Method.

How LOB differs from a Gantt chart 🔗

Most project managers are familiar with the Gantt or bar chart. It tells you how long each activity takes. What it does not tell you is whether activity rates are synchronized with each other – whether the pace at which Task A is being completed allows Task B to begin without waiting or clashing.

A LOB chart takes a different approach. It plots time along the horizontal x-axis and the project’s main work areas or units along the vertical y-axis. Each activity appears as a line, and critically, the slope of that line indicates the rate of progress: a steep slope means the activity is advancing quickly, while a shallow slope signals a slower pace. Planned completion dates are represented as dashed lines, while actual completion dates appear as solid lines. The gap between them immediately reveals schedule variance – no calculations needed, no digging through rows of data.

As Mosaic Projects explains, LOB shows the rate at which work must be undertaken to stay on schedule, and the relationship between one trade or process and the next is defined by the space between the lines. If one group falls behind, it will visibly converge toward the line of the following group – a clear signal for intervention before a collision happens.

The four core steps of applying LOB 🔗

Implementing LOB is a structured process. The Project Management Institute outlines four foundational steps in applying the LOB technique to repetitive projects:

1. Develop a delivery schedule 🔗

This is also referred to as the Master Production Schedule (MPS) – a schedule of planned deliveries that defines when units or outputs are expected to be completed. It sets the overall production targets that every downstream activity must support. This schedule provides the reference baseline against which all progress will later be measured.

2. Develop a plan of operation 🔗

Here, the project is broken down into its individual repetitive tasks, each with a defined sequence and duration. For an agribusiness operation, this might mean mapping out activities such as soil preparation, sowing, irrigation, pest management, harvesting, and post-harvest handling – each performed identically across multiple plots or batches. The logical dependencies between these tasks are established so the correct sequencing is locked in before scheduling begins.

3. Develop a progress chart 🔗

This is where the LOB diagram is actually constructed. Each activity is plotted as a line on the chart based on its required production rate. The required rate for each activity is derived by working backwards from the delivery schedule – if a final output must be delivered by a specific date, each preceding activity must be completed at a rate that supports that deadline. Planning Engineer describes this as a backward-calculation process: start from when the last activity must finish and compute the latest acceptable start time for each preceding step, ensuring work continuity without unnecessary gaps.

4. Analyze the results 🔗

Once the chart is drawn and actual progress is plotted, managers compare the two sets of lines. According to AcqNotes, this analysis helps with four key management tasks: comparing actual progress against the formal plan, examining deviations and gauging their severity, receiving timely information about trouble areas, and forecasting future performance. This step is where LOB shifts from being a scheduling tool to a management control instrument.

Key components of a LOB chart 🔗

Understanding the chart itself is essential to using LOB effectively. Three elements do most of the analytical work:

Planned progress line 🔗

This line represents the scheduled rate of task completion over time, derived from the delivery schedule and the plan of operation. It is the benchmark – the pace at which every activity should be moving if the project is on track.

Actual progress line 🔗

This line is updated continuously as work proceeds, reflecting the real-time rate of completion. When plotted on the same chart as the planned line, any divergence becomes immediately visible. A line running ahead of plan signals surplus capacity or accelerated production; a line falling behind signals a delay that needs attention.

Buffer and deviation 🔗

The space between activity lines in a LOB chart represents a time buffer – it ensures that one crew or process does not overtake and interfere with the one ahead of it. If two activity lines begin to converge, it is a warning that a collision – a bottleneck or resource clash – is imminent. Mosaic Projects notes that maintaining this buffer by adjusting production rates or staging is a key decision point for the management team.

Why LOB is especially valuable for repetitive projects 🔗

LOB is purpose-built for situations where the same set of activities is performed multiple times across different units, locations, or batches. In agribusiness, this maps directly to operations like multi-field crop production, greenhouse growing cycles, poultry or livestock batch management, and food processing lines.

ProjectManager.com notes that LOB enhances coordination between teams, reduces waste, and improves overall productivity by focusing on flow, timing, and sequencing. It reduces idle time by organizing tasks so that crews and resources move continuously from one unit to the next without waiting. This steady flow cuts down the downtime caused by delays, access issues, or interference between teams.

For manufacturing and assembly-line contexts specifically, MyExamSolution points out that LOB ensures each station or process operates in harmony with the others, preventing delays in one stage from cascading into subsequent stages. This is the production equivalent of balanced workflow – the kind that lean manufacturing principles, including Just-in-Time (JIT) systems, also aim for.

Additionally, Vargas and Moreira (2015), writing for PMI, demonstrated that combining LOB with Start-Finish (SF) task relationships – inspired by JIT concepts from the Toyota Production System – can serve as a “pulling mechanism” for activities, stripping out unnecessary anticipation and keeping resources committed only when genuinely needed. This integration significantly reduces total resource days and associated labor costs.

Benefits and limitations 🔗

What LOB does well 🔗

The advantages of LOB are well-documented across industries. AcqNotes highlights that LOB gives managers a clear picture of the volume of work taking place at any given time in a specific area, supports easier cost and time optimization analysis, simplifies schedule updates, and improves the management of subcontractors and external resource providers. Because the entire project can be visualized on a single chart, Turbo Chart notes that LOB requires far fewer individual tasks and relationships than traditional Critical Path Method (CPM) scheduling – making it significantly easier to build, read, and communicate.

CrewCost also emphasizes that LOB is not limited to large operations. Small and medium-sized enterprises can use it to improve scheduling efficiency, enhance resource allocation, and reduce bottlenecks – as long as their project involves repetitive activities with known production rates.

Where LOB has limits 🔗

LOB is not a universal solution. It works best when tasks are genuinely repetitive and when reliable production rate data is available. TheMBA.Institute identifies data accuracy as one of the key challenges: if the durations and dependencies of work elements are estimated inaccurately, the LOB chart loses much of its value. Creating and managing the chart also adds complexity as the number of activities grows.

Importantly, as AcqNotes points out, LOB charts show where a problem exists but not necessarily why it exists or what the solution should be. The chart is a diagnostic instrument, not a prescriptive one. Managers still need to investigate root causes and make informed decisions about corrective action.

LOB in the context of agribusiness project management 🔗

In agribusiness, repetitive processes are the norm rather than the exception. Whether it is managing irrigation cycles across dozens of fields, coordinating harvesting crews moving from one plot to the next, or overseeing sequential processing steps in a grain or dairy facility, the challenge is always the same: keeping all activities synchronized so that no crew is idle, no batch is waiting, and no downstream process is starved of inputs.

LOB addresses this directly. By making the production rate of each activity visible – and by making convergence or divergence between activities immediately apparent – it enables agribusiness project managers to anticipate bottlenecks before they cause costly disruptions. Combined with modern scheduling software (tools like TILOS and VICO Control support LOB-based scheduling), the technique can scale from small farm operations to large integrated supply chains.

The key takeaway is this: LOB does not replace sound judgment in project management. It gives managers the visual clarity and factual basis to exercise that judgment more effectively – at the right time, and in the right places.

What do you think? If you were managing a multi-field crop production cycle or a batch-based food processing operation, which activity would you consider the most critical to monitor on a LOB chart – and why? Is there a repetitive process in your agribusiness context where a traditional Gantt chart has left you with blind spots that LOB might address?

References

1. https://acqnotes.com/acqnote/tasks/line-of-balance
2. https://www.designingbuildings.co.uk/wiki/Line_of_balance_(LOB)
3. https://mosaicprojects.com.au/WhitePapers/WP1021_LOB.pdf
4. https://www.pmi.org/learning/library/scheduling-optimization-balance-10614
5. https://planningengineer.net/the-application-of-line-of-balance-lob-method-in-construction-projects-using-excel-tool/
6. https://www.projectmanager.com/blog/line-of-balance-scheduling-construction
7. https://www.myexamsolution.com/2024/12/line-of-balance-lob-for-production.html
8. https://turbo-chart.com/line-of-balance-chart
9. https://crewcost.com/blog/quick-guide-to-the-line-of-balance-technique/
10. https://themba.institute/management-of-machines-and-materials/the-line-of-balance-lob-for-production-control-and-monitoring/