Pekanbaru - PT Hutama Karya Infrastruktur (HKI) has successfully applied Lean Construction principles in the construction of the Trans-Sumatra Toll Road (JTTS), specifically in the Pekanbaru-Dumai (Pekdum) Section 2A. This success has resulted in improved productivity and efficiency, compared to previous project management methods. “Our focus was on a critical section of the underpass work at STA 28+150,” explained Mardiansyah, Head of the Control Department at HKI and one of the initiators of Lean Construction implementation at the company. Mardiansyah clarified that the underpass work at STA 28+150 had initially experienced a delay deviation of 1.46%. “This delay was caused by the pile driving for the 60 cm diameter Spun Pile. It led to a chain of delays, which impacted the superstructure work above it. This delay was predicted to have a cumulative effect on the subsequent work stages, ultimately affecting the completion of the toll road construction,” he explained.
To complete 100%, the underpass work still had 58 activities, known as the work breakdown structure (WBS), which accounted for 67.4% of the overall progress. The time required to complete these 58 activities was 120 days. “In the original plan, these 58 activities were to be completed in 90 days, not 120. This resulted in a potential delay of 30 days and a cost increase of 3.42%,” Mardiansyah added. These 58 activities were then grouped into three categories based on Lean Construction principles: Value Added (VA), Non-Value Added (NVA), and Essential Non-Value Added (ENVA). “VA includes activities that are agreed upon and proven to add value to the work, while NVA refers to waste. ENVA represents activities that must be performed, even though they don’t add value, such as material handling,” he clarified. The grouping of activities into these categories was done through the Value Stream Mapping (VSM) process and interviews with those involved in the work process. “This grouping process involved intensive communication with the core project team, including the Project Manager, project managers, subcontractors, vendors, and other partners,” he added.
Once the activities were grouped, the first focus was to examine the NVA (waste) activities and develop strategies to eliminate them. “We identified 7 waste elements in the process, 3 related to transportation, 3 related to waiting activities, and 2 in inventory activities, all of which were part of the current state map,” he said. A detailed calculation showed that eliminating all these wastes would reduce the delay duration by 50%.
After effectively addressing the waste, the next step was to apply Lean Construction tools to the VA and ENVA activities. “The goal is simple. All VA and ENVA activities must be treated using Lean tools to optimize the reduction of delays and minimize cost increases,” he explained. Several Lean tools were used in this project, such as Daily Huddle Meetings, Just-in-Time, Last Planner, Working Structuring, 5S, Prefabricated, Crash Program, and others.
By eliminating waste from the NVA activities and applying Lean tools to the VA and ENVA activities, the Lean Construction concept was effectively implemented and positively impacted progress. “The remaining underpass work, which would have taken 120 days with the conventional method, was completed in just 85.5 days—4.5 days ahead of the original 90-day schedule,” Mardiansyah stated. With the faster completion, HKI avoided the risk of penalty for delay. “The penalty is 1/1000 of the contract value. This means that for each day of delay, we would be fined a fraction of the total contract value. Fortunately, with Lean Construction, we avoided the penalty, and the project owner was satisfied because the work was completed ahead of schedule,” Mardiansyah concluded.
As a result of this achievement, HKI recently received the Innovation Appreciation Award from Koran Sindo and Sindonews.com in the “Best Product” category.
