Forklift Call System 2026 | Cutting Wait Time on the Floor

“The forklift never comes.” “I called, but I have no idea who is actually responding.” These complaints grow louder in every plant and warehouse as output increases. A forklift call system fills the information gap between the people who need something moved and the people who actually drive the trucks. The options range from battery-powered wireless call buttons, through notifications pushed to smartwatches, all the way to automatic task dispatch linked to a warehouse management system, and the cost gap between the simplest and the most elaborate build is more than tenfold. This article organises how to choose and in what order to deploy, from the perspective of a company running a factory or warehouse in Thailand.

What a forklift call system actually is

A forklift call system is a general term for any arrangement that reliably delivers a “please move this” request from somewhere on the floor to a forklift operator, and then decides who will respond. It is not a single product category. It covers everything from a push button paired with a beacon light, up to a setup that reads the warehouse management system and tells each truck where to go next.

Boil the underlying problem down and it splits three ways. First, the request does not arrive at all. A line operator can shout, but the shout dies in the noise of running equipment. Second, the request arrives but nobody is assigned. Broadcast a call over two-way radios and everyone assumes somebody else will take it, or three trucks converge on the same aisle. Third, the requester never gets confirmation. The line operator waits beside the pallet with no idea whether a truck is on its way.

Which of those three you are trying to solve determines the shape of the system. Put the other way round, if you start comparing products before deciding which problem is yours, you simply add equipment that has features nobody uses.

How this differs from a general factory call system

For factory call and notification systems in general, our article on how to choose a factory call and notification system covers the basic architecture and the selection criteria. Calling an inspector for a quality defect, or calling a parts supplier when a bin runs empty, involves a fixed counterpart who is usually in a fairly predictable place.

Forklift calls differ in one decisive respect: the person being called is always in motion. Operators shuttle between the warehouse and the production floor, and they leave the seat during handling. Walking to a fixed beacon light, or driving back to the office to pick up a paper instruction sheet, generates travel every single time. On top of that, a forklift is a vehicle carrying heavy loads through shared aisles, so the way a notification is received is a safety question in itself. Any design that makes an operator stare at a screen while driving is an accident waiting to happen.

Three types of call, by origin

Sorted by where the call originates, there are three types.

The first is the human-initiated call. A line operator or a truck driver presses a button, or raises a request from a terminal. This is the easiest to deploy and the easiest to get buy-in for.

The second is the equipment-initiated call. A sensor detects that a finished-goods pallet is full and automatically raises a pickup request. The manual step disappears, but you now have to install sensors and tune thresholds.

The third is the system-assigned call. A warehouse management system or a production control system generates the transport task from scheduled receipts, shipments and process progress, before anyone has called at all, and assigns it to the best-placed vehicle. This delivers the largest effect and requires the most integration design.

Why forklift calls become the bottleneck

In-plant logistics is the first function to jam when output rises, because headcount does not scale in proportion. A Hitachi article on in-plant logistics makes the same point: in plants whose layout has not changed in years, or where higher volume has complicated material flow, the act of moving things becomes the bottleneck itself.

That bottleneck surfaces as three kinds of lost time.

The first is waiting time on the requesting side. Between the moment a pallet fills and the moment it is collected, that process has nowhere to put the next unit. The second is empty running on the operator side: drive to the call, set the load down, and, with no next call queued, drive back to the staging point. Those round trips accumulate. The third is search time. Time spent circling the warehouse without knowing which pallet is where disappears without ever being recorded.

In one published case of movement-path analysis using indoor positioning, long dwell in a single area was read as a sign of waiting for work, while dwell spread across multiple areas was read as a sign of excessive travel. A forklift manufacturing plant that ran the same analysis reported cutting the number of forklifts in active use by roughly 30 percent once the overlaps between paths and waiting were resolved. Getting the call mechanism right can be the cheapest way to raise transport capacity without buying more trucks.

Sorting the options into three layers

Before you line products up side by side, sorting the functions into layers makes the decision much faster. This article treats a forklift call system as three layers.

The layers stack. Layer 2 alone or Layer 3 alone does not function, because notifications cannot flow where no call is raised, and assignment cannot reach an operator who never receives the notification. The sections below walk through each layer with real equipment, a sense of cost, and its limits.

Layer 1, wireless call buttons and andon display

The fastest thing to deploy is a battery-powered wireless call button paired with a beacon light or buzzer. No cabling work is required, so it retrofits into an existing building.

One published example of a low-cost wireless call system sold in Japan quotes a base indoor range of roughly 50 metres, extendable by 30 metres per repeater, with up to four repeaters. Indicative unit prices in that example are 2,200 JPY for a waterproof call button, 7,000 JPY for a number display, 6,950 JPY for a flashing chime, and 7,800 JPY for a repeater. These are tax-inclusive Japanese domestic prices for one product family; procuring in Thailand adds import costs and local distributor pricing.

A concrete deployment: truck drivers arriving at a warehouse dock calling an operator. In one logistics operator’s case study, in a warehouse of roughly 60 metres by 50 metres where operators move constantly, transmitters were installed at the entrance and in the office, with receivers and a beacon buzzer inside the warehouse. A long press on the transmitter sends a number and the buzzer sounds continuously until a second long press clears it. The reported result was that pressing one button was enough to summon a responder, which removed the unevenness in work throughput.

On the imported-equipment side, systems that link push-button units to signal towers over radio are commercially available. Each button unit also runs on battery power, so it can be mounted on a moving asset such as a forklift or a tugger train and used as a stand-alone system. The vendor also describes an operator pressing their own button unit to report status directly to other units without going through a signal tower at all.

Where Layer 1 stops

Layer 1 makes the existence of a call visible. The flip side is that it does not decide who answers. An operator out of sight of the beacon never sees it, and when several calls stand at once there is no way to tell which to serve first. If you intend to run on Layer 1 alone, you must pre-assign areas to individuals. For a site small enough to run on area ownership, Layer 1 by itself delivers real value.

Layer 2, personal notification to smartwatches and vehicle terminals

Layer 2 delivers the call to a moving individual. Wrist-worn terminals that notify by text plus vibration have been used against exactly the complaints heard on noisy production floors: “we call and nobody notices” and “it is never clear who is supposed to respond.” Feel the vibration, glance at the screen to see who it is for, press to accept. The whole sequence completes one-handed.

For selecting the wearable device itself, our article on using smartwatches on the factory floor covers battery life, wearability and the rest of the evaluation criteria. Three points are specific to forklift use.

First, design so that nothing has to be operated while driving. Keep the in-motion signal to vibration and a simple colour or symbol, and pair it with an operating rule that content is read and accepted only after stopping. Second, it must be operable with gloves on. Check touch sensitivity and the presence of physical buttons on real hardware. Third, plan the charging routine. On two or three shifts, decide up front whether devices are handed over at shift change or issued to individuals who charge them personally, or you will find flat devices scattered around the floor.

Vehicle-mounted terminals are the other option. One product example is a tablet-type terminal for forklift mounting with a 10.1-inch touch panel and wireless LAN, working alongside a long-range scanner and an RFID reader. With that setup, the round trip to the office to collect a paper instruction sheet disappears and instructions are pushed to the floor in real time. Progress is reported the moment work completes, so the management side always sees a picture that matches the floor. The terminal can also read a code from 3 metres away from the seat, which removes the need to dismount at all.

Wrist-worn and vehicle-mounted are not mutually exclusive. A vehicle terminal carries more information and suits handling work, but it is invisible when the operator has left the seat. Positioning the wrist device as the complement that covers that gap makes the investment much easier to justify.

Layer 3, automatic transport task dispatch through WMS integration

Layer 3 treats a call as a task and lets the system assign it. A warehouse management system or production control system already holds scheduled receipts and shipments, stock locations and process progress. Start from that data and you can generate a transport task before anyone calls.

Automatic assignment needs three pieces of information on the system side. First, the content of the task, meaning what moves from where to where. Second, the position of each vehicle. Third, the state of each vehicle, meaning whether it is empty, loaded, or mid-handling. The second and third are the ones that get skipped, and the result is the half-finished state where tasks are generated automatically but assignment still happens over the phone.

There are several positioning methods. One published comparison describes a wireless LAN method with access points at 20 to 30 metre spacing, and an ultrasonic method with fixed stations at 5 metre spacing. UWB and pedestrian dead reckoning are also used, sometimes in combination. Higher accuracy means denser installation and higher cost, so decide the required accuracy by asking whether knowing the area is enough, or whether you genuinely need to know which rack the truck is standing at. For call assignment, area-level accuracy is usually sufficient.

State is most reliably captured from operations on the vehicle terminal. Confirm at pick-up and at set-down and the empty-to-loaded transitions get recorded. You can automate this with sensors, but starting from terminal operations and automating once the routine has settled produces fewer failures.

For choosing the sensors themselves, our article on selecting IoT sensors for factories is a useful companion.

What is specific to forklifts, travel paths and safety

Chase call efficiency alone and the safety dimension drops out. A forklift carries heavy loads through shared aisles, so call design cannot be separated from travel-path design.

In figures compiled by the Japan Industrial Vehicles Association from the Ministry of Health, Labour and Welfare occupational accident statistics, forklift-related accidents causing death or injury numbered 1,989 in 2023, of which 22 were fatal. By accident type, caught-in or crushed accounted for 35.4 percent of the death-and-injury cases, struck-by for 27.3 percent, and falls for 11.9 percent. Call design bears most directly on the struck-by category.

Introducing a call system can push travel up or down. It pushes up when calls are raised at fine granularity and each one triggers a separate round trip. It pushes down when several requests can be consolidated into one circuit. The same system can move total in-plant travel distance in opposite directions depending on the assignment rules, and that has to be understood before deployment, not after.

The design points to hold on the safety side are as follows.

Make content review a stopped-vehicle activity. The notification itself may arrive while moving, but reading the detail and accepting the task happens after stopping.

Express the call origin at area granularity. Making an operator track precise coordinates on a screen pulls their eyes to the screen.

Do not concentrate calls on paths that cross pedestrian routes. If path analysis has identified the crossings, simply not staging trucks just before them already lowers contact risk.

Prevent multiple trucks converging on one call. This is the classic Layer 1 failure, and where there is no acknowledgement mechanism, area ownership has to cover for it.

In Thailand, qualification and training management also feeds into call design. Thailand has no government-issued forklift licence. Under the Occupational Safety and Health Act B.E. 2554 (2011) and the Ministerial Regulation on machines, cranes and boilers B.E. 2564 (2021), Part 4 Section 40, the employer carries the legal responsibility to train each operator, assess competence and certify them, with enforcement by the Department of Labour Protection and Welfare. Under that framework the employer already holds the record of who is permitted to operate which vehicle. Cross-reference that record inside the assignment logic and you structurally prevent a transport task from being sent to an uncertified operator.

How this relates to andon

Anyone evaluating a call system runs into the question of how it relates to andon. Andon originally exists to make line abnormalities visible by colour and position, and our article on andon and visual management systems covers it in detail.

The relationship is easiest to hold this way: andon shows a state, while a call system decides who should move. Andon display alone does not determine the responder. A call system alone does not show the overall picture of how many requests are currently queued across the site.

In practice, if a plant already runs andon, the realistic starting point is to add one colour for transport requests. Layer 1 then exists without adding any equipment, and it rides on the morning meeting and the daily management cycle you already run. Keep the transport request as its own distinct colour and it also serves as the signal source when Layer 2 and Layer 3 are added later.

Call granularity and operating rules

Rule design fails more often than product selection. These five items should be decided before any equipment is chosen.

Decide who may raise a call. Opening it to every operator gives maximum flexibility but invites a flood of calls in which priority disappears. Whether to restrict it to process leaders or open it to all depends on how mature the floor discipline is.

Decide the unit of a call. Whether one pallet is one call, or one process worth of material is one call, changes the daily volume several times over. Change the volume and you change both the number of notification devices required and the complexity of the assignment logic.

Decide the response deadline. Without a target for how many minutes a call may stand before acceptance, the system becomes a device that merely records calls. Only once a deadline exists does an overrun become visible as an exception.

Decide the escalation path. Where does an overdue call go, to the supervisor’s device or to a list screen in the office. Leave this blank and overruns are noticed by nobody.

Decide how a call is cancelled. Without a way to clear a mis-press or a call that circumstances have made unnecessary, the floor starts ignoring the display. A call that cannot be cancelled will always end up as a formality.

Practical points for deploying in Thailand

Several assumptions differ from a Japanese deployment.

Start with the language of display and notification. Operators on the floor are predominantly Thai speakers, while the management side mixes Japanese and English speakers. If you adopt text-based notification, translation upkeep becomes an ongoing operating load. Design with numbers and colours as the primary channel and text as secondary and the system tolerates adding or swapping languages. The longevity of the Layer 1 number display on real shop floors owes a great deal to this property.

Next, the radio environment. Warehouses packed with steel racking and plants full of large equipment produce attenuation and interference. Assume the Layer 1 range will not match the catalogue figure and leave headroom to add repeaters. If you are considering wireless LAN positioning, do not assume the existing access point layout can be reused as-is.

Third, the path to automation. Market research puts the Thai autonomous forklift market at 101 million USD in 2026, growing to 317 million USD by 2031, a compound annual growth rate of 17.8 percent. The global figure over the same period is forecast at 9.7 percent, so Thailand is growing at roughly twice the world rate. If there is any chance of putting driverless forklifts into part of the site later, hold the call task information in a form that can be dispatched to both human-operated trucks and automated vehicles, and the eventual transition gets much easier.

Fourth, handover. Assume operator turnover, and keep the call operating rules explainable on a single sheet of paper. Rules that live only in one person’s head collapse the day that person transfers.

A model case, cost and effect

The following works through cost and effect using a fictional company. These figures are an independent estimate produced for this article, not real statistics or survey results.

The subject is “Company G”, a Japanese-owned electronic components manufacturer with a plant and adjoining warehouse in eastern Thailand. Eight forklifts, ten operators across two shifts. Transport requests are made by internal phone and by voice, and operators are dispatched by broadcast over two-way radio. Roughly 120 transport requests arise per day, and the average wait from request to arrival is 12 minutes.

The effort cost is an independent estimate assuming a system integrator engineer day rate of 30,000 THB to 50,000 THB, quoted separately from equipment. The equipment and effort columns are cumulative up to each row. Taken as increments alone, Layer 2 adds 70,000 THB of equipment and 8 person-days, and Layer 3 adds 240,000 THB of equipment and 25 person-days.

The effect side is deliberately split by layer.

What matters is that each layer shortens the wait for a different reason. Layer 1 removes the walk to fetch someone and the time spent searching. Layer 2 lets operators notice calls while in motion, and the returned acknowledgement removes uncertainty for the requester. Layer 3 decides the next destination on the system side, which removes both the scramble over who takes a request and the return trip to a staging point.

Layer 3 carries one further effect that is independent of waiting time: less empty running. This estimate assumes 15 minutes per vehicle per day, or 120 minutes, meaning 2 hours, across eight trucks. That arises from optimising transport sequence and reaches the result by a different route than the reduction in requester waiting time.

It is worth testing the assumptions. If the wait reduction turns out to be only half of what is assumed, the through-Layer-3 saving becomes 3.5 minutes per request and 420 minutes, or 7 hours, per day. That factor applies only to waiting time, however. The 120 minutes of empty-running reduction stems from the change in transport sequence and is not affected by this factor. Applying a single sensitivity factor across effects of different nature makes the conclusion needlessly pessimistic.

A staged deployment path

There is no need to build all three layers at once. The following order lets you insert an investment decision at each step.

Stage one is making the present state visible. For one to two weeks, record on paper the time each transport request is raised, who raised it, which operator responded, and the arrival time. No capital spend is required. This yields the daily request volume, the distribution of waiting times, and the time bands and processes where waiting concentrates. Go into product selection without this record and you lose the ability to verify any effect at all.

Stage two is a limited Layer 1 deployment. Put call buttons and beacon lights only into the processes where waiting concentrates, and run them under area ownership. A month of operation is enough to compare against the recorded waiting times. If no effect appears, then the problem was never the calls but the number of trucks or the layout, and you can redirect the investment on evidence.

Stage three is extension to Layer 2 or Layer 3. If waiting fell under Layer 1 but operators still miss calls, go to Layer 2. If the residual problems are prioritisation and empty running, go to Layer 3. Where a WMS already exists, start with a read-only integration and defer assignment automation, which keeps the scope of system modification small.

Common failures

The same failures recur.

The first is notifying everyone. A design in which every operator’s device sounds at once is simply a digitised version of the radio broadcast, and the nobody-moves problem survives intact. Build in either acknowledgement or area ownership.

The second is not setting a response deadline. Without one, delays never surface as exceptions and the records merely accumulate.

The third is not designing the cancel and complete operations. If calls never clear, the display saturates and the floor stops looking at it.

The fourth is assuming operation while driving. Beyond the safety exposure, if the floor decides the system is dangerous and stops using it, the investment is simply wasted.

The fifth is over-specifying positioning accuracy. Rack-level accuracy is an inventory management requirement; call assignment is frequently satisfied at area level. Mix the requirements and only the cost grows.

The sixth is adding a new mechanism without deciding how it divides work with the existing andon and radios. Give the floor three ways to call and only the most familiar one gets used.

Frequently asked questions

What is a forklift call system?

It is a general term for any arrangement that reliably delivers a transport request raised on a plant or warehouse floor to a forklift operator, and decides who will respond. It spans everything from wireless call buttons with beacon lights up to configurations that read a warehouse management system and assign transport tasks automatically. Because it is not a single product category, comparison should start by deciding which layer of function you are actually buying.

How much does it cost to deploy?

It varies widely by configuration. In the model case estimated independently for this article, a Layer 1 configuration of wireless call buttons and beacon lights came to 90,000 THB to 130,000 THB, a Layer 2 configuration adding smartwatch notification to 400,000 THB to 600,000 THB, and a Layer 3 configuration including WMS-integrated automatic assignment to 1,390,000 THB to 2,090,000 THB. Note that design and setup effort, rather than hardware, accounts for most of the total.

Are our existing two-way radios not enough?

The strength of a radio is that one call reaches everyone at once. The structural weaknesses are three: nobody is assigned, nothing is recorded, and response deadlines cannot be managed. Where call volume is low and two or three operators can see what each other is doing, radios work perfectly well. The point at which volume grows and it stops being obvious who moved is the point to consider systemising.

Is it safe to have operators receive notifications while driving?

Receiving is fine while moving, but it must be paired with an operating rule that content is read and the task accepted only after stopping. The basic split is vibration plus a simple colour or symbol while in motion, with detail reviewed once stopped. Avoid any design that asks a driver to track fine coordinates on a screen, because it pulls their eyes off the aisle.

Can this be deployed without a WMS?

Layer 1 and Layer 2 can be deployed stand-alone with no WMS. Layer 3 automatic assignment needs a system holding the source data for transport tasks, so it presupposes integration with a WMS or a production control system. If a WMS is on the roadmap, keeping call records from the Layer 1 and Layer 2 stage gives you real data to design task definitions from later.

What should we watch for on a Thai site?

Making numbers and colours the primary channel, and reducing dependence on text, is practically useful. Most operators are Thai speakers while the management side mixes Japanese and English speakers, so a text-centric design turns translation upkeep into a burden. Thailand also has no government-issued forklift licence, and the employer carries responsibility for training, competence assessment and certification, so there is scope to reflect who may operate which vehicle inside the assignment logic.

How should we measure the effect?

Start by recording, for one to two weeks before deployment, the time each request is raised, who raised it, who responded and the arrival time. Take the same measurements afterwards and compare the average time from request to arrival along with the spread of the distribution. Look at the tail as well as the average, because averages bury the requests that were left waiting far too long.

Summary

A forklift call system is easier to choose once you stop treating it as a single product and start treating it as a combination of three layers: origination and display, personal notification, and task assignment. Layer 1 deploys fast and cheap but does not decide who responds. Layer 2 reaches moving operators but does not solve prioritisation. Layer 3 solves assignment but requires integration design with upstream systems.

Three things are specific to forklifts. The person being called is always in motion. The way notifications are received bears directly on safety. And total in-plant travel distance rises or falls depending on the assignment rules. Compare products purely on features without holding those three, and you add equipment the floor will not use.

As a sequence, record the present state on paper to understand the distribution of waiting times, deploy Layer 1 only into the processes where waiting concentrates, and then extend to Layer 2 or Layer 3 according to the nature of what remains. Getting the call mechanism right can raise transport capacity without adding a single truck.

Where the waiting actually occurs in your operation, and how far up the layers you should build, depends on layout, output volume and the operating rules you run today. TOMAS TECH builds IoT and production management systems for factories and warehouses in Thailand, and we are happy to discuss forklift calls and transport task visibility. You are welcome to get in touch through our contact page even at a stage where no specific product has been shortlisted.

References

• QQ Bell, complete guide to low-budget wireless call systems for factories
• WERMA Signaltechnik, AndonWIRELESS product page
• Pacific Shonan, case study on calling forklift operators with a wireless andon system
• MTS TECH BLOG, warehouse management using forklift-mounted terminals, part one
• Genba Kaizen Lab, forklift accidents, cases, incidence and causes
• CEC, RaLC logistics simulation software, capturing and analysing worker and forklift positions
• MarketsandMarkets, Thailand Autonomous Forklift Market
• GESTA, Forklift Operator Certification in Thailand
• DIS Service and Solution, wrist-worn wearable terminals so floor information is never missed
• Hitachi, what in-plant logistics is, the issues companies face and where to improve