ICT活用で工期短縮を実現：土木・建設プロジェクト成功のための施工効率化ポイント

はじめに

In the civil engineering and construction industry, in recent years the critical issue has been how to shorten construction schedules. With labor shortages, rising material costs, and responses to work-style reform-related laws applied to construction starting in 2024 (the so-called “2024 problem”), the environment surrounding sites has changed dramatically. To proceed efficiently with limited personnel, it is essential to review traditional methods and improve productivity through the use of ICT (information and communication technology). The Ministry of Land, Infrastructure, Transport and Tourism also launched [i-Construction（アイ・コンストラクション）](https://www.mlit.go.jp/tec/i-construction/) in 2016, and the industry-wide push for DX (digital transformation), including mandatory use of BIM/CIM in public works, has begun in earnest.

However, shortening construction periods is not simply a matter of speeding up work; it is important to do so while ensuring quality and safety. Unreasonable schedules can lead to staff exhaustion and mistakes, which may actually extend the schedule due to rework. This article explains key points for achieving schedule reductions and construction efficiency using ICT, aimed at site supervisors of small and medium contractors, construction managers at general contractors, and engineers involved in municipal works. We focus particularly on cloud-based schedule management (schedule sharing, progress “visualization,” rapid response to changes, stakeholder collaboration) and simplification of field surveys using smart devices, photogrammetry, drones, and high-precision GPS. We cover the benefits of introducing each technology, concrete operational methods, quantitative effects, case studies, tips for on-site adoption, and cautions when introducing them. At the end of the article, we also introduce how the recently noted LRTK (smartphone + high-precision GNSS receiver) makes simple surveying that can contribute to cloud schedule management, field survey efficiency, and faster reporting.

クラウド工程管理によるスケジュール共有と進捗可視化

The first step to shortening construction periods is to enhance schedule (program) management. Traditionally, Excel or paper schedules were used, and site supervisors adjusted daily based on experience. However, this approach tends to cause delays in information sharing and transmission errors, making it difficult for the entire site to respond quickly to progress deviations. Cloud-based schedule management has attracted attention. By centrally managing schedules in the cloud and enabling all stakeholders—site, head office, subcontractors, etc.—to check the latest information at any time, wasted waiting time and rework can be reduced.

Key points of cloud-based schedule management are as follows:

• Real-time schedule sharing: By putting schedules online, each person in charge can always access the latest schedule. If a schedule change occurs on site, it is instantly shared with everyone, preventing discrepancies in understanding.

• Progress “visualization”: By reporting and sharing daily work progress from smartphones or tablets, delays or slack compared to the plan can be grasped at a glance. If a process is falling behind, early support measures can be taken, allowing project-wide, bird’s-eye responses.

• Rapid response to changes: Weather, design changes, or delayed material deliveries can be addressed quickly. If schedules are revised in the cloud, stakeholders receive immediate notifications, allowing plans to be rearranged on the spot to minimize unnecessary waiting time.

• Strengthened stakeholder collaboration: Sharing information in the cloud from prime contractors to subcontractors, material suppliers, and owners enables the whole team to act as one. For example, sharing delivery schedules avoids duplicate arrangements for heavy machinery and materials, leading to smoother progress. Communication between remote sites and head office is also streamlined, contributing to reduced frequency of regular meetings and business trips.

Introducing cloud-based schedule management has produced actual results in shortening construction periods. For example, on one site with many subcontractors, a cloud-based schedule management tool was introduced to share work details and delivery schedules in real time. As a result, material delays and work overlaps were prevented in advance, enabling a short construction period without disrupting the overall flow. In another case, company A adopted an AI-equipped schedule management system that automatically optimized schedules considering weather forecasts and personnel conditions, reportedly reducing work time by 30% and helping cut overtime. By accelerating information sharing and coordination through cloud use, unnecessary losses are reduced and directly contribute to shorter schedules and lower labor costs.

For cloud schedule management to take root, it is important that all site staff become proficient with the tool. Choose a system that is easy to operate from smartphones or PCs, and provide sufficient education and support during initial implementation. It is effective to trial the system on some projects first, verify the effects, and share success stories before rolling it out company-wide. Once the habit of sharing up-to-date information becomes established, you can move away from management that relies on “individual intuition and experience,” making handovers and personnel changes smoother. Digitizing schedule management also has major benefits for work-style reform: reducing unnecessary overtime and weekend work and managing sites efficiently improves employees’ working conditions and supports staff retention. It truly forms the foundation for “people-first management.”

スマートデバイスの活用で業務効率アップ

Using smart devices (smartphones and tablets) is effective for information sharing and record-keeping on site. Until now, construction drawings and checklists were mainly paper-based, but simply enabling viewing and input of drawings and documents on a tablet can greatly increase efficiency. For example, one construction company centralized drawings in the cloud so site supervisors and workers could always check the latest drawings on handheld tablets. As a result, construction mistakes due to overlooked design changes dropped to zero, and the approval flow for drawings was digitized, greatly reducing the time required for checks. The need to distribute and replace paper drawings disappeared, and the paperless approach also reduced printing and transportation costs.

Simplifying field reporting and records using smartphones is also notable. Previously, photos taken on site with digital cameras had to be plotted on maps, notes taken, and then pasted into Excel at the office to create reports. Now there are smartphone apps that automatically record location and date/time when taking photos and link the photos to a site map in the cloud. For example, because shooting position and orientation are saved automatically, it is immediately clear where and in which direction a photo was taken. This eliminates the need to take notes on site and to compile photo ledgers at the office, removing recording errors for shooting locations. If daily reports and checklists can be input from smartphones, double data entry is avoided and the time spent on reporting tasks is dramatically shortened.

Main benefits of smart device use are summarized below:

• Immediate sharing of the latest information: Drawings, work instructions, and schedules are centrally managed in the cloud, allowing anyone to access the latest version from anywhere, on site or in the office. Even with design changes or schedule revisions, updates are instantly distributed to everyone, preventing mistakes caused by discrepancies in understanding.

• Simplification of site record tasks: Photos and reports taken and entered from smartphones or tablets are automatically shared and organized in the cloud. This removes the need for paper notes and post-entry on PCs, reducing transcription errors and omissions. Voice input or checkbox-style forms can make it easier for veterans unfamiliar with IT to input data.

• Paperless efficiency: Digitizing drawings and documents cuts costs and labor associated with printing, binding, and mailing. The need to travel to site for drawing replacements is reduced, saving travel time. Necessary materials are all stored on the tablet, eliminating the burden of carrying paper drawings or documents around site.

• Remote situation awareness: Photos and progress data aggregated in the cloud can be checked in real time by supervisors at head office or by owners. This enables appropriate instructions and support even when the person in charge is not on site, speeding up decision-making and reducing the number of meetings.

When introducing smart devices, pay attention to site communication environments and device handling. In mountainous or underground locations with poor reception, prepare apps that work offline or have later synchronization functions. Equip tablets with waterproof and shockproof cases to prevent damage on site. For older workers unfamiliar with IT, have younger staff provide follow-up or share screens to ease resistance. To avoid the perception that digitization has increased workload, minimize the dual operation period of paper and electronic systems, make operational rules clear, and roll out the system so everyone experiences benefits.

写真測量（フォトグラメトリ）とドローンで現地調査を効率化

In surveying and field investigation, ICT-driven efficiency gains have advanced significantly. In particular, the combination of photogrammetry and drones has revolutionized wide-area topographic understanding and as-built control. Traditionally, surveying large sites required surveyor teams to spend many days measuring numerous points and drafting drawings. Surveying in mountainous or steep and dangerous terrain also imposed heavy burdens and risks. By using drone aerial photogrammetry, however, detailed data for the entire site can be acquired automatically from the air in a short time, and the surveying time can be reduced to about one-quarter to one-tenth of conventional methods in some cases. For example, in a demonstration by the Ministry of Land, Infrastructure, Transport and Tourism, drone-based inspection surveying of a river section of about 25 km (15.5 mi) completed a task that previously took 4 hours in 25 minutes (about 1/10). Since steep slopes where people cannot enter can be surveyed remotely and safely, it reduces worker burden and improves safety.

Numerous images taken by drones can be processed with dedicated software (SfM: Structure from Motion) to produce high-precision three-dimensional terrain models. This allows construction of a “digital twin” of the site that includes fine details often overlooked previously, enabling office-based measurement of arbitrary dimensions and generation of cross sections. Once the existing conditions are fully digitized, the need for additional re-surveys is reduced, decreasing rework. Using obtained point cloud data and 3D models in design enables accurate understanding of terrain gradients and geological conditions for planning, contributing to a reduction in design-change risks during construction.

Drones and photogrammetry are also used for as-built control. On one civil engineering site, an automated system was introduced that used a drone to photograph the entire site from above after work each day and calculated embankment volumes from the images. As a result, the time required for as-built measurement was reduced to about one-quarter of the previous time, allowing daily progress to be quantified. Previously, calculating as-built quantities took several days, and by the time the site agent submitted reports, conditions might have changed. After DX introduction, as-built conditions can be checked in real time and as-built reports and schedule revisions can be made immediately. Sharing 3D data with owners has also smoothed as-built inspections and payment procedures, speeding up reporting and approval work.

The main benefits of photogrammetry and drone use are as follows:

• Significant reduction in survey work time: Drone aerial imaging and automated processing can complete surveys that would take days by manpower in hours to minutes. In one MLIT case, starting survey time was reduced from about 6 weeks to 3 weeks (about 50% reduction).

• Fewer personnel required and labor savings: One drone and an operator can survey wide areas, reducing required personnel. There are reports that tasks that previously required at least three people for survey management could be handled by two, making it an effective countermeasure against labor shortages.

• Safety at dangerous locations: Data can be obtained unmanned in areas where people cannot enter, reducing the risk of accidents in crash-prone terrain or high-altitude work. Drone imaging can replace scaffolding for high inspections, combining safety and efficiency.

• Improved accuracy with 3D data: Using point clouds and models from photogrammetry allows accurate, surface- and volume-based understanding of as-built conditions. This reduces measurement omissions and recording errors, preventing rework and incorrect quantities. The acquired data can be used as an asset for future maintenance and long-term quality assurance.

When introducing drones or photogrammetry, attention must be paid to legal compliance under aviation law and to ensuring operator skills. Drone flights may require prior permission and license acquisition, so plan accordingly. Also, precise 3D analysis requires high-performance PCs or cloud services, so consider data processing environments. Even so, these technologies can be expected to deliver efficiency gains that exceed initial investment, and the government provides subsidy programs to promote ICT construction. If it is difficult to operate drones or perform analysis in-house, partnering with specialized survey companies makes introduction relatively straightforward. The important thing is to start small, experience the effects, and gradually expand usage.

現場でICTを定着させるためのポイント

Even if new technologies are introduced, they are meaningless unless used on site. To maximize the schedule-shortening effects of ICT, it is important to assimilate new tools into site habits and culture and ensure they take root. Here are some points to consider.

• Clarify the problems to be solved: Saying vaguely “promote DX” can backfire by increasing site burden. First, identify your company’s or site’s issues and set priority improvement points such as “delayed schedule management,” “inefficient surveying,” or “burden of document preparation.” Then select ICT tools that directly address those issues (schedule management systems, drone surveying, electronic whiteboard apps, etc.).

• Incorporate site feedback: When choosing tools and defining operation methods, actively solicit opinions from site supervisors and workers who will actually use them. Bottom-up ideas from the field are more likely to be accepted smoothly than top-down imposition. Appointing a “promotion leader” responsible for digital initiatives from the site and involving them in the implementation project is also effective.

• Choose easy-to-use tools: Select tools with as simple an operation as possible that fit site work. Compare Japanese language support, availability of support, and whether tasks can be completed on a smartphone alone. Overly complex systems tend to be avoided on site, so it is wise to start with the minimum necessary, intuitive features.

• Introduce in phases to build familiarity: Rather than digitizing all sites and tasks at once, start with trial introduction at small sites or for part of the work. For example, test cloud schedule management on a single project, analyze effects and issues, and then roll it out to other sites to reduce failure risk.

• Education and support for site staff: Provide initial training so that all site staff can learn basic operations when introducing new tools. Train in-house “super users” as role models and establish a system where staff can ask questions when in trouble. Prepare manuals and operation videos and conduct regular follow-up training to promote adoption.

• Transition plan from legacy processes: Abolish or reduce paper-based and manual tasks as much as possible with ICT introduction. Prolonged dual operation of paper and electronic systems increases site burden. For example, stop paper report submissions soon after electronic reporting begins, and cease updating whiteboard schedules after introducing cloud schedules—set clear timelines for switching.

• Visualize and share effects: After introduction, quantitatively measure and share how much time has been shortened or efficiency improved. Showing results in numbers—e.g., “meeting time halved,” “as-built reporting time shortened by three days”—boosts site motivation. Share success stories in company newsletters or morning meetings to disseminate know-how across sites.

• Use subsidies and grants: There may be government or municipal subsidies for DX promotion in construction, such as i-Construction-related subsidies or IT introduction subsidies for SMEs. Utilizing such programs can reduce initial costs, so actively gather information. Vendor campaigns and free trial periods are also useful.

Finally, when promoting ICT introduction, keep in mind the balance with quality and safety management. If efficiency is pursued at the expense of inspection processes, mistakes or accidents could ultimately extend schedules. Use data obtained from ICT to strengthen quality checks beyond previous levels. For example, require photo-attached completion reports in the cloud daily and have a third party perform checklist-based quality verification—using ICT to enhance quality and safety is essential. DX is a means to an end, and real effects appear when it is combined with craftsmen’s skills and management know-how.

おわりに

We have covered ICT utilization points for shortening schedules and improving operational efficiency, from cloud schedule management to field survey DX. By effectively using these technologies, you can drastically reduce wasted time and effort while maintaining and improving quality and safety and increasing productivity. Even amid severe labor shortages, ICT can enable sites to operate with fewer people, helping build a sustainable construction operation that aligns with work-style reform. Shortening construction periods not only reduces costs and improves profit margins but also brings secondary benefits such as increased owner satisfaction and reduced burden on site staff (less overtime and secured weekly holidays). DX has truly become an indispensable success factor in the future of the construction industry.

One particularly noteworthy solution lately is LRTK, which combines a smartphone and a high-precision GNSS receiver. Finally, we introduce how LRTK can contribute to cloud schedule management, field survey efficiency, and faster reporting. LRTK stands for a technique where a palm-sized RTK-GNSS receiver is attached to a smartphone or tablet to enable positioning with centimeter-level accuracy (half-inch accuracy). Dedicated apps offer various functions such as measuring position coordinates and point cloud data, tagging photos with coordinates, and AR (augmented reality) simulation displays. Tasks that formerly required specialized surveying equipment and qualifications are designed so that anyone can perform them routinely, and media reports describe a quietly growing trend of LRTK as a “universal surveying device, one per person.”

With LRTK, for example, site supervisors themselves can measure as-built conditions and quantities with a smartphone and immediately share that data in the cloud for reporting. Measured coordinate values can be plotted on a cloud map with a single button, allowing office personnel to check them in real time via a web browser. This eliminates the time loss of “waiting for the survey team’s results” before proceeding to the next step. Combined with photogrammetry, advanced uses are possible, such as overlaying LRTK-measured check points on point cloud models obtained by drone for accuracy verification. LRTK also automatically tags captured site photos with positioning information, dramatically streamlining the aforementioned photo management tasks. It is reported that this can eliminate the time spent on paper notes and subsequent report creation and prevent errors in recording shooting locations. The revolutionary functions enable labor savings and speed-ups in reporting.

By incorporating new technologies like LRTK, the quality and quantity of data accumulated through cloud schedule management and field surveys can be greatly enhanced, lifting project-wide management to the next level. Site DX using ICT will not be completed overnight, but by gradually digitizing familiar tasks, steady results in schedule shortening and construction efficiency will emerge. Please consider incorporating these points into your projects to realize “smart construction” that meets the times. Make the most of ICT to achieve both efficiency and high quality and increase the success rate of civil engineering and construction projects.