How to Prepare Your Thailand Factory for High-Mix, Low-Volume Production: Flexible Line and System Design

Target Audience: Factory managers, plant managers, and production control managers at Japanese manufacturers operating in Thailand, as well as those responsible for driving DX at manufacturing sites from corporate headquarters. This article is also a valuable reference for shop-floor personnel struggling with the transition to high-mix, low-volume production.

“In the past, we could run tens of thousands of units of the same part number in a single month. Now we have to switch between more than ten part numbers in a single week.” This kind of comment is being heard with increasing frequency at Japanese-affiliated factories in Thailand. Whether in automotive parts, electronic components, or food-related manufacturing, the shift to high-mix, low-volume production has become an unavoidable trend. The drivers behind it include smaller order quantities, greater diversity in customer needs, supply chain restructuring, and deeper market penetration within emerging economies.

The problem is that line configurations and systems were built under the logic of the high-volume, low-variety era and have largely remained unchanged. Long changeover times, difficulty tracking where inventory is located, inability to see cost and profitability by part number, paper-based work instructions that cause confusion every time a part number changes — when these challenges pile up, adapting to high-mix, low-volume production becomes an enormous drain on cost and labor hours.

This article explains the concepts behind line design and system design that Thailand-based factories need to prepare for high-mix, low-volume production, grounded in real shop-floor conditions. It covers a wide range of practical topics: specific applications of IoT, automation, inventory management, and paperless operations; how to structure investments utilizing BOI incentives; and how to present proposals to corporate headquarters in Japan.

1. Why High-Mix, Low-Volume Production Is Accelerating Now

The environment surrounding manufacturing in Thailand is undergoing significant change between 2025 and 2026. Growth forecasts remain cautious, and the World Bank has identified multiple risk factors for the Thai economy’s outlook. In this external environment, the procurement behavior of customer companies (buyers) has also shifted.

In the past, “large orders and long lead times” were standard. Today, buyers demand procurement of “the quantity needed, when it is needed, to the required specification.” In the automotive sector, electrification and model diversification are advancing, creating the need to produce a large number of variants on a single platform. In electronic components, shorter product lifecycles mean that a supply structure capable of handling low-volume, high-variety orders directly translates into competitive advantage. In food and consumer goods, deepening the domestic Thai market and diversifying exports are progressing simultaneously, and SKU counts continue to grow.

Furthermore, with ongoing labor shortages and rising wages in Thailand, it is becoming increasingly difficult to sustain changeover operations, inspection tasks, and daily reporting that rely heavily on manual labor. The only way to increase part-number changeover capacity without adding headcount is to take action on both line design and system design simultaneously.

S&P Global’s PMI surveys show that order trends in Thai manufacturing have become increasingly uneven across product categories, and demand leveling has remained difficult. In this environment, factories capable of handling high-mix, low-volume production are precisely the factories that buyers will continue to choose.

2. Typical Problems That High-Mix, Low-Volume Production Creates on the Shop Floor

When factories attempt to move toward high-mix, low-volume production, a chain of problems tends to emerge on the shop floor. Each issue individually may be a “long-standing problem,” but as part numbers and changeover frequency increase, the severity and frequency of these problems escalate sharply.

Prolonged Changeover Times

Replacing tooling and fixtures, switching raw materials, swapping out work instructions, changing equipment parameters — in the high-volume, low-variety era, these tasks only needed to be completed a few times per month. As high-mix, low-volume production advances, changeovers occur every day, sometimes multiple times per day. At 30 minutes per changeover, three changeovers a day means a net loss of 1.5 hours of production time. Calculated over a year, this amounts to hundreds of hours of lost productivity.

Inability to Track Inventory Location and Quantity

As part numbers multiply, managing raw material, work-in-process, and finished goods inventory becomes dramatically more complex. Production begins without knowing “where that component is” or “how much of this raw material remains,” and it is only mid-process that a shortage is discovered, causing a stoppage — this scenario occurs repeatedly. Duplicate stock holdings, expired materials, and obsolescence also increase.

Inability to See Cost and Profitability by Part Number

With high-mix, low-volume production, the structure of raw material costs, processing costs, and changeover costs differs for each part number. Even if overall revenue is maintained, there is a risk of continuing to produce without knowing which part numbers are generating profit and which are operating at a loss. A common feeling on the shop floor is “we’re busy but not making money.”

Work Instructions and Quality Records Cannot Keep Up

Paper work instructions and quality checklists functioned adequately when part numbers were few. But as part numbers increase, management of “which work instruction is the current version” and “where the quality records for this part number are stored” starts to break down. Cases where factories cannot respond immediately when Japanese headquarters or customers request quality traceability are also increasing.

Shop-Floor Confusion and Over-Reliance on Key Personnel

Know-how for handling multiple product types becomes concentrated in experienced workers, and setups cannot proceed or quality judgments cannot be made without those individuals — over-reliance on key personnel advances. In the Thai manufacturing environment, where employee turnover is high, this represents a particularly serious risk.

3. Line Design Principles for High-Mix, Low-Volume Production: Building a “Change-Resilient Factory”

The foundation of line design suited to high-mix, low-volume production is to “build in mechanisms that minimize the cost of change.” The following outlines the major design principles that can be implemented on the shop floor.

Cell Production and U-Shaped Lines

Conveyor-based lines designed for high-volume, low-variety production require stopping and reconfiguring the entire line every time a part number changes. Cell production systems and U-shaped lines, by contrast, form small, self-contained production units staffed by a small number of workers, minimizing the scope of impact when part numbers change. Adoption of cell production in Thailand is increasing in automotive parts and electronic equipment assembly processes.

Implementing SMED (Single Minute Exchange of Die)

SMED — reducing changeover times to single-digit minutes (under 10 minutes) — is one of the kaizen activities that most directly addresses high-mix, low-volume production. Typical measures include converting internal setup tasks to external setup (completing preparatory work before stopping the line), standardizing and color-coding tooling and fixtures, and recording work procedures on video.

Standardizing and Modularizing Equipment

Selecting versatile equipment and modular equipment capable of handling multiple part numbers — rather than equipment dedicated to specific part numbers — reduces the cost of accommodating additional part numbers. Initial investment may be somewhat higher, but the long-term ROI of versatile equipment is frequently superior.

Integrating Process Design with Systems

As discussed later, line design alone is insufficient for addressing high-mix, low-volume production. Determining which part numbers to run and in what sequence (scheduling), tracking the location and quantity of raw material and work-in-process inventory, and capturing quality records in real time — integrating these elements with systems is what allows the physical flexibility of the line to deliver its full value.

4. The Core of System Design: Inventory Visibility and Digitalization of Work Instructions

The role that systems play in addressing high-mix, low-volume production is to “keep the complexity of the shop floor in a manageable state.” The more part numbers increase, the more human memory and paper documents fail to keep pace with management demands.

Real-Time Inventory Tracking Through an Inventory Management System

An inventory management system capable of tracking raw material, work-in-process, and finished goods inventory in real time by part number is the foundational infrastructure of a high-mix, low-volume factory. Preventing situations such as “the parts that should be on that shelf aren’t there” or “a shortage was only discovered after production had already started” requires a mechanism that updates the system with every inbound and outbound movement, centralizing management of part number, lot, quantity, and storage location.

By integrating an inventory management system with reorder point management, the system can automatically detect stockout risks and issue advance alerts. The greater the number of part numbers, the greater the value of this automatic alert function.

Digital Management of Work Instructions and Quality Records Through Paperless Operations

Digitalizing paper work instructions, standard operating procedures, and quality checklists is a particularly important investment in the context of high-mix, low-volume production. Having a system where the correct, up-to-date version of work instructions automatically appears on a worker’s tablet every time a part number changes significantly reduces the risk of workers performing tasks based on incorrect instructions.

Digitalization of quality records is becoming indispensable as traceability requirements intensify. Recording in a system which lot of raw materials was used, which worker confirmed which steps at which process — this enables rapid root-cause investigation when customer complaints or product recalls occur.

Unifying KPIs Through Equipment Operation Management

In a high-mix, low-volume line, tracking uptime, downtime, and defect rates by part number forms the starting point for improvement activities. Implementing an equipment operation management system enables cross-part-number comparison and analysis of how much downtime occurs during changeovers for each part number, and which lines have the highest defect rates.

Without operational data, shop-floor improvement discussions devolve into impressions — “things feel busy” or “defects feel high.” When the numbers become visible, improvement priorities become clear, and realistic investment return calculations become achievable.

5. Applying IoT and Automation to High-Mix, Low-Volume Lines

IoT and automation are the means to realize “a system that adapts to change without relying on manual labor” in addressing high-mix, low-volume production. However, introducing IoT and automation to every process does not solve everything by itself. Determining return on investment clearly and deploying incrementally from the highest-impact processes is critical.

Automated Collection of Equipment Status via Sensors

Automatically collecting the operating, stopped, and alarm status of equipment through sensors attached to machines significantly reduces the labor hours workers spend manually recording daily reports. Having the system automatically detect part-number changeover timing and accumulate actual changeover time data builds the foundational data for changeover improvement activities automatically.

Real-Time Inventory Updates via Barcodes and QR Codes

Attaching barcodes or QR codes to labels on raw materials, work-in-process, and finished goods, then scanning them with handheld scanners, reflects inventory inbound and outbound movements in the system in real time. Using tablets or smartphones, inventory information can be checked and updated from anywhere on the shop floor. This is one of the measures with relatively low implementation cost and high likelihood of producing results.

Automating Changeover Tasks with Collaborative Robots (Cobots)

Assigning specific repetitive tasks — such as workpiece picking, temporary placement, and alignment — to cobots reduces the human labor burden during changeovers. Cobots are easier to install and reconfigure than conventional industrial robots and are relatively flexible in accommodating part-number changes. However, because standardized operations are a prerequisite, the correct sequence is to first organize changeover processes using SMED, then consider robotization.

Demand Forecasting and Production Scheduling via AI and Data Analytics

Combining order data, inventory data, and lead time data to optimize demand forecasting and production scheduling using AI or statistical methods enables on-time delivery while minimizing changeover frequency. However, this is a step to be undertaken only after the inventory management and operational data infrastructure is in place. AI applications without a data foundation cannot succeed.

6. Comparison Table: Investment Priority Matrix for High-Mix, Low-Volume Production Readiness

Measure Category	Effect on High-Mix, Low-Volume	Investment Cost	Implementation Difficulty	Recommended Priority
Inventory Management System Implementation	Reduction of stockouts and excess inventory; real-time inventory visibility by part number	Medium	Medium	Top Priority
Paperless Work Instructions and Quality Records	Prevention of changeover errors; traceability assurance	Medium	Medium	Top Priority
Equipment Operation Management (IoT Sensors)	Visualization of changeover and downtime; collection of foundational improvement data	Medium–Low	Low–Medium	High Priority
SMED Changeover Improvement	Substantial reduction of changeover time; lower changeover cost	Low (primarily labor hours)	Medium	High Priority
Barcode / QR Code Inventory Scanning	Real-time inbound/outbound updates; reduction of human error	Low	Low	High Priority
Collaborative Robot (Cobot) Implementation	Reduction of changeover and picking labor hours	High	High	After Data Infrastructure Is In Place
AI Demand Forecasting and Scheduling	Optimized changeover frequency; prevention of stockouts and excess inventory	High	High	After Data Infrastructure Is In Place

7. Structuring Investments Using BOI Incentives

The Thailand Board of Investment (BOI) offers incentives including corporate income tax exemptions and duty-free equipment imports for investments that strengthen the competitiveness of manufacturers, including those involving automation and AI. By combining equipment and system investments for high-mix, low-volume production readiness with BOI applications, the effective payback period on investments can be significantly shortened.

The key point with BOI is not to “decide on the investment first, then think about applying” but rather to “design the investment plan with BOI application as a prerequisite.” IT investments such as inventory management systems, operation management systems, and paperless tools may qualify for BOI incentives if certain requirements are met. Specific applicability requires prior consultation with BOI, but being aware of this from the planning stage expands the options available for application.

There is also a practical benefit: utilizing BOI makes it easier to obtain approval for investment proposals at Japanese headquarters. The explanation that “by leveraging Thai government incentives, we expect to recover the investment within three years” provides compelling grounds for cautious corporate finance departments.

8. Presenting to Japanese Headquarters: Building an Investment Plan Around a Three-Year Payback

When a Thailand-based operation proposes a high-mix, low-volume production investment to corporate headquarters, the most important thing is to move beyond qualitative appeals such as “things will be more convenient” or “we’ll have better visibility.” What headquarters needs is a quantitative basis for the investment amount and expected payback.

For an inventory management system, this means presenting the current inventory level, stockout frequency, and disposal costs due to excess inventory in figures, and calculating projected improvements following system implementation. For example: “Of current inventory-related costs totaling X baht per month, Y% consists of excess inventory and stockout response costs. Assuming the inventory management system reduces this by Z%, we expect cost savings of X baht per month from the first year.”

For paperless operations, the calculation should include costs of printing, distributing, disposing of, and reprinting work instructions; labor hours spent on quality traceability compliance; and loss costs from part-number changeover errors. For an operation management system, calculate current changeover time and projected improvement in hours × number of machines × operating days, and convert the actual increase in production capacity into a monetary value.

Building the plan around “whether the investment can be recovered within three years” makes the proposal easy for headquarters to evaluate. Additionally, supplementing the proposal with quantitatively difficult-to-measure risk reduction benefits — BOI cost reduction, lower quality complaint risk, and mitigation of workforce turnover risk (through digitalization of know-how) — allows the rationality of the investment to be demonstrated from multiple angles.

9. Failure Patterns in High-Mix, Low-Volume DX — and How to Avoid Them

Failures in system and automation investments aimed at high-mix, low-volume production tend to follow several common patterns. Being aware of them in advance prevents repeating the same mistakes.

Failure Pattern 1: Attempting to Implement a Large System All at Once

The approach of “first rolling out an ERP or integrated core system across the entire company simultaneously” often takes a long time to take root in Thai shop-floor environments and may end up being abandoned mid-implementation due to resistance from the shop floor, without ever being fully utilized. The mitigation is to start small — one process, one warehouse, one form — and create a success experience where the shop floor feels “this actually works,” then expand horizontally.

Failure Pattern 2: Proceeding Without Involving Shop-Floor Personnel

Japanese headquarters selects and implements a system, and the shop floor receives only the instruction to “use it.” Thai shop-floor workers will not proactively use a system they were not involved in choosing. The mitigation is to involve shop-floor leaders from the system selection stage, ensuring the system is recognized as “a system we can use comfortably.”

Failure Pattern 3: Collecting Data Without Using It

IoT sensors are installed and operational data becomes available, but no one is looking at the data and it is not being used for improvement — this situation is common. Data collection is a means; the goal is improvement and decision-making. The routine of “who looks at the data, when, for what purpose, and how they use it to make decisions” must be designed before implementation.

Failure Pattern 4: Disconnect Between Japanese and Local Language

Work instructions and quality checklists are digitalized, but created only in Japanese, making them incomprehensible to Thai workers. In Thai shop-floor environments, Thai-language support and visualization (procedure explanations using photos and videos) are the keys to adoption.

Failure Pattern 5: Overly Optimistic Assumptions About Payback

Assuming that improvement effects will appear immediately after system implementation and building this into the headquarters investment plan is a common mistake. In reality, a certain amount of time is required for system adoption, establishment of operational routines, and improvement of data accuracy. Investment plans should be conservatively structured to incorporate a “six-month to one-year ramp-up period.”

10. Phased Implementation Roadmap: A Three-Phase Approach to High-Mix, Low-Volume Readiness

Investment in high-mix, low-volume production readiness does not need to be carried out on a large scale all at once. Proceeding in three phases allows you to confirm results at each phase before moving to the next step.

Phase	Estimated Timeframe	Key Measures	Outcome Indicators to Confirm
Phase 1: Visualization	3–6 months	Inventory management system deployment in one warehouse; pilot installation of operation sensors on one line; paperless work instructions (starting with one part number)	Improvement in inventory accuracy; number of stockout occurrences; accumulation of actual changeover time data
Phase 2: Improvement and Expansion	6–12 months	SMED changeover improvement; full-warehouse expansion of inventory management; full-line expansion of operation management; digitalization of quality records	Changeover time reduction rate; OEE improvement rate; improvement in inventory turnover; reduction in quality record labor hours
Phase 3: Optimization	12–24 months	Data-driven production scheduling optimization; evaluation of cobots and automated equipment; pilot AI implementation; integration with accounting DX	Cost visibility by part number; confirmation of actual investment payback; identification of further improvement opportunities

Upon completion of Phase 1, presenting an interim report to headquarters — “Phase 1 results (in numbers) + Phase 2 and beyond investment plan” — makes it easier to obtain approval for continued investment.

11. Integration with Accounting DX: Connecting Shop-Floor Data to Management Financials

A situation where DX for high-mix, low-volume production ends at shop-floor improvement without being reflected in the numbers reviewed by management makes it difficult to obtain ongoing investment approval. By integrating shop-floor data collected through inventory management, operation management, and paperless operations with accounting and cost management systems, shop-floor improvements become visible as management financials.

Concretely, this could include integration of manufacturing cost by part number (allocation of material costs, processing costs, and changeover costs), real-time tracking of inventory valuation, and cost recording of defects and disposal. This enables management to confirm “which part numbers are generating profit and which have persistently high costs.”

At many Japanese-affiliated companies in Thailand, the shop-floor production management system and accounting system operate independently, with accounting staff manually reconciling the figures at month-end. Reducing this “month-end manual reconciliation” and enabling management to grasp financial figures in near real time directly accelerates the speed of management decision-making.

12. TOMAS TECH’s Perspective

TOMAS TECH provides comprehensive IT system support to Japanese manufacturers, logistics companies, and retailers across ASEAN from its base in Thailand. In the context of high-mix, low-volume production readiness, the following outlines the areas where we can provide day-to-day practical support.

Inventory Management System PEGASUS centralizes management of part numbers, lots, and storage locations, enabling real-time inventory updates via barcodes and QR codes. It serves as the foundational platform for resolving the problems common in high-mix, low-volume factories — “we don’t know what is where or how much” and “we only discovered the shortage after production had started.” It provides a system capable of absorbing the complexity that comes with managing inventory across a growing number of part numbers, including reorder point management, inventory alerts, and inventory history tracking.

i-Reporter (Paperless Application) replaces paper forms — work instructions, standard operating procedures, quality checklists, and daily reports — with digital forms on tablets and smartphones. It enables operations where the correct, up-to-date version of work instructions is automatically displayed on workers’ devices at the time of part-number changeover, directly preventing changeover errors and ensuring traceability. It also supports Thai-language display and embedding of photos and videos, helping facilitate adoption among Thai workers.

Operation Management System, combined with IoT sensors, collects and visualizes line operating status, stoppages, and changeover times in real time. It enables cross-part-number analysis of how long changeovers take for each part number and where defects are concentrated. It can also be used as a data collection tool for SMED activities.

Smartwatch System instantly delivers equipment alarms and abnormality notifications to workers’ smartwatches. In high-mix, low-volume lines, equipment abnormalities that occur during changeovers are easy to miss; instant notifications prevent delayed responses.

Our approach is not to propose large-scale implementation from the outset. Our standard method is to start small — one warehouse, one line, one form — confirm results in numbers on the shop floor, and then expand. We have the on-the-ground capability in Thailand to provide end-to-end support: shop-floor adoption assistance, Japanese-language support, and assistance with investment payback calculations for headquarters reporting.

For consultations regarding high-mix, low-volume production readiness, please contact TOMAS TECH. After listening to your current challenges, we will propose an approach tailored to your site’s specific needs.

Summary

High-mix, low-volume production is an unavoidable trend for Japanese manufacturers in Thailand. When smaller order quantities, greater diversity in customer needs, and labor shortages converge, attempting to respond while maintaining the line design and system design of the high-volume, low-variety era causes costs and labor hours to surge and deepens shop-floor confusion.

The key to addressing this lies in simultaneously advancing both line design (cell production, SMED, versatile equipment) and system design (inventory management, operation management, paperless operations). A phased approach — starting small, confirming results, and then expanding — is both realistic and effective for Thai shop floors, far more so than large-scale, all-at-once implementation.

For investment decisions, building a quantitative plan centered on recovery within three years, and actively leveraging BOI incentives, creates favorable conditions on both fronts: headquarters approval and actual investment cost reduction.

Even if you are at the stage of “not knowing where to start,” TOMAS TECH can work with you from the initial current-state analysis. Let us take the first step together in transforming the shift to high-mix, low-volume production into a source of competitive advantage.