MES vs ERP in Japanese Plants: In-House Systems and Excel

You ask a Japanese supplier, or your own parent plant in Japan, for lot genealogy or work-in-process data "from the MES." What comes back is an Excel file. The plant has a seisan kanri shisutemu (生産管理システム, production management system), it does not quite match what you call MES or ERP, and some of the data you asked for lives in spreadsheets and paper logs. Before you design an interface or a data request, it helps to know how these systems are usually split up in Japan.

The short answer: ERP (enterprise resource planning) plans and accounts for the whole company, while MES (manufacturing execution system) runs and records the work on the shop floor. ERP decides what to make, when, and how many. MES turns that plan into work orders for machines and operators, records what actually happened, and sends the results back. Many Japanese plants, especially small and mid-sized ones, cover both jobs with a single production management system, a Japanese package, an in-house system, or a mix of spreadsheets and paper.

This guide covers the MES vs. ERP split, where each sits in the ISA-95 model, what you are likely to find in a Japanese plant, and what to confirm before you exchange data with one. It ends with a checklist, a list of questions, and an email template.

Contents

1. MES vs. ERP: The Basics
2. Where MES and ERP Sit: The ISA-95 Levels
3. What You Will Find in a Japanese Plant
4. What Plants Expect from MES and ERP
5. Why These Projects Often Struggle
6. Exchanging Data with a Japanese Plant: What to Check
7. Limits of This Guide
8. FAQ
9. Sources

MES vs. ERP: The Basics

What ERP Does

ERP manages a company's core business processes in one database: accounting, sales, purchasing, inventory, production, and HR. Oracle describes it as software for running day-to-day business activities such as accounting, procurement, and supply chain, with data from many departments collected once into a "single source of truth." When an order comes in, it updates inventory and the production plan. When goods ship, it updates sales and accounts receivable.

ERP grew out of manufacturing. Material requirements planning (MRP) software appeared in the 1960s, it evolved into manufacturing resource planning (MRP II) in the early 1980s, and Gartner coined the term "ERP" in 1990. A tool for calculating parts requirements became a system for managing the resources of the whole company.

What MES Does

MES runs and controls production on the factory floor. It takes the production plan from ERP, breaks it into specific instructions for equipment and operators, and records what happened so the results can go back up. Fuji Electric describes MES as the system that runs closest to the production floor, one that makes the manufacturing process visible and helps a plant use people, materials, and money without waste, instead of depending on the experience of particular employees.

At its core, MES records which product was made, on which machine, by whom, from which material, and under which conditions.

Why a Plant Needs Both

If ERP already has a production module, why add MES? ERP is good at calculating which items to make by when, and which parts to order and when. But the shop floor changes every day: a machine breaks down, a material lot is bad, an operator is absent, or a rush order jumps the queue. Reacting to those changes within minutes or hours, and recording the results accurately, takes a system that runs close to the floor. That is the job of MES.

Figure 1: ERP vs. MES

ERP handles company-wide planning and business management. MES handles execution and records in the plant.

ERP

MES

ISA-95 level

Level 4 (business management)

Level 3 (manufacturing operations)

Main scope

Accounting, sales, purchasing, inventory, HR

Work orders, progress, quality, equipment

Time scale

Months, weeks, days

Hours, minutes, seconds

Main users

Management, administration, sales

Production, quality assurance, production engineering

Typical data

Order quantities, inventory value, cost

Lot history, inspection results, machine status

Rollout unit

Whole company (or group)

Often one plant or one line

Functions overlap between products, and each company draws the boundary for itself.

Where MES and ERP Sit: The ISA-95 Levels

The usual reference for placing MES and ERP is ISA-95, a standard from the International Society of Automation (ISA) for integrating business systems with plant control systems. It is published internationally as IEC 62264; the first edition of IEC 62264-1 came out in 2003 and the second in 2013. As Siemens summarizes it, ISA-95 splits plant and business activities into five levels:

• Level 0: the physical production process
• Level 1: sensing and manipulating the process (sensors and actuators)
• Level 2: monitoring and control (PLCs, SCADA)
• Level 3: the workflows that produce the product (MES)
• Level 4: the activities needed to manage the business (ERP)

For the PLCs that handle control at Levels 1 and 2 in Japanese plants, see Mitsubishi vs. Keyence vs. Omron vs. Siemens PLCs.

Figure 2: ISA-95 Levels and Where MES and ERP Sit

MES sits between ERP, which runs the business, and the control systems that run the equipment.

Level 4: ERPBusiness management: orders, purchasing, inventory, accounting

Production plan ↓ / ↑ Production results

Level 3: MESWork orders, progress, quality, traceability

Work orders ↓ / ↑ Machine and measurement data

Level 2Monitoring and control: PLC, SCADA, HMI

Level 1Sensors and actuators

Level 0Physical production process

Based on Siemens, "ISA-95 framework and layers."

Plans Flow Down, Results Flow Up

The direction of the data matters most. MES breaks the ERP production plan into work orders for each process and machine, and the control systems run the equipment. In the other direction, MES collects machine status and measured values and sends them back to ERP as production results. The two systems also work on different clocks: ERP plans by the month, week, or day, while MES handles shop-floor data by the hour, minute, or second. That gap in time scale is why ERP alone cannot run a plant.

ERP and MES are often built by different vendors. ISA-95 standardizes the boundary between them, meaning which system holds which data and in what format it is exchanged, to cut the cost and errors of connecting them.

In practice, where a company draws that boundary shapes the whole project. If the detailed sequence of jobs lives in ERP, a schedule change on the floor follows a different procedure than if it lives in MES. Another common problem is inventory held twice, once as "ERP inventory" and once as physical stock on the floor, with numbers that no longer agree. Deciding up front which system is the system of record avoids this. When you connect to a Japanese plant, it is also one of the first things to ask.

The MESA-11 Functions

The best-known breakdown of MES functions is MESA-11, from the industry group MESA International (Manufacturing Enterprise Solutions Association). Published in the mid-1990s, it sorts the core functions of MES into 11 areas. A plant does not need all 11 in one product; many add the functions they need one at a time. MESA has since published broader models that tie MES to the rest of the enterprise, and the idea of MES now reaches beyond the plant to the supply chain.

Figure 3: The 11 MES Functions in MESA-11

The 11 functions are easier to follow in three groups: planning and dispatch, execution and records, and quality and analysis.

Planning and dispatch

01Resource allocation and statusAssign and track equipment, tools, and materials

02Detailed schedulingSet the job sequence for each process

03Dispatching production unitsRelease lots and jobs to the floor

04Document controlManage work instructions, drawings, and recipes

Execution and records

05Labor managementTrack operator assignments, shifts, and qualifications

06Data collection and acquisitionCollect machine and job results

07Process managementMonitor process flow and respond to problems

08Maintenance managementManage maintenance plans and equipment history

Quality and analysis

09Quality managementAnalyze inspection data and control quality

10Product tracking and genealogyTrace the production history of each product

11Performance analysisAnalyze utilization, yield, and other results

Based on Fuji Electric, "What Is MES?" and MESA International. The three groups are an editorial grouping.

Plants often give the highest priority to product tracking and genealogy (traceability). When a defect turns up, the question is how fast the plant can find every product made from the same material lot or on the same machine. That answer sets the scope of a recall and affects customer trust. In food, pharmaceuticals, and auto parts, customers commonly ask suppliers for production history records.

What You Will Find in a Japanese Plant

The "Seisan Kanri System": Between ERP and MES

A term you will often hear in Japan is seisan kanri shisutemu (生産管理システム, production management system). It usually means a system that covers orders, production planning, material ordering, process control, inventory, and costing. Some products combine ERP's production module with part of MES. Many small and mid-sized Japanese manufacturers do not separate ERP and MES at all and run the plant on one production management system. Production control staff run it day to day and usually define the requirements when a new system comes in. Production engineering connects equipment and designs data entry on the floor, quality assurance manages traceability and inspection data, purchasing uses the ERP purchasing functions, and the IT department plans, selects, and maintains the systems. For what production control does, see production control in Japan.

Figure 4: Business Systems in a Manufacturing Company

Knowing what each system covers makes the overall picture easier to follow.

ERPIntegrates core business: accounting, sales, purchasing, inventory

Production management system (seisan kanri)Covers orders, planning, material ordering, process control, and cost

MESWork orders, results collection, quality and history records in the plant

SCMOptimizes the flow of goods from procurement to sales

PLMManages product data such as designs and bills of materials

SCADA / HMIMonitors and operates equipment and plants

SCM: supply chain management. PLM: product lifecycle management. SCADA: supervisory control and data acquisition. HMI: human-machine interface.

SCM (supply chain management) looks beyond one company's walls to suppliers, logistics, and customers, while ERP manages resources inside the company. If your question is about how a Japanese customer's plan reaches you as a supplier, see supplier kanban vs. MRP with Japanese customers.

Japanese Packages, Mostly Installed On-Site

Small and mid-sized Japanese manufacturers often run domestic packages that are little known outside Japan. In a 2024 survey of Japanese companies with annual sales under JPY 50 billion, Nork Research found that the five products with more than 5% share (single answer) among companies with a production management system were Otsuka Shokai's Seisan Kakushin series, OBIC's OBIC7, NEC's EXPLANNER/J and /Z, Factory-ONE Dennou Kojo (developed by Osaka-based Ekusu and also sold by NEC), and Fujitsu's GLOVIA iZ. Larger groups are more likely to run global ERP such as SAP. Ask for the product name and version early, because it tells you what interfaces and export formats are realistic.

The same survey shows that most of these systems still run on-premises. Of 452 companies with a production management system already installed, 47.1% ran a package on their own premises and 9.7% used SaaS. For future plans, on-premises packages fell to 40.2% and SaaS rose to 10.9%. Cloud MES and ERP are spreading because they need no in-house servers, cost less up front, and are updated by the provider. Even so, a cloud-to-cloud API connection is not a safe assumption with a Japanese plant.

Figure 5: How Japanese SMEs Run Their Production Management Systems

Packages installed on-site dominate; SaaS (cloud services) is about one in ten.

Package, on-premises47.1%

Package, in a data center35.2%

Package, on IaaS or hosting13.7%

SaaS9.7%

452 companies with annual sales under JPY 50 billion and a production management system installed; multiple answers allowed. Surveyed July–August 2024. Source: Nork Research (2024, Japanese).

A likely reason for staying on-premises is that production management is tied directly to running the plant. Companies weigh what happens during a network outage and the need for real-time links to equipment.

In-House Systems, Excel, and Paper

Many Japanese plants cover MES-type functions without an MES product. Some use systems developed in-house to fit their own processes. Others combine spreadsheets with paper forms: daily production reports, check sheets, and progress boards. How common each approach is varies widely, and there is no single figure for it, but you should expect a mix rather than one clean system.

For you, this has practical effects:

• Data may be typed in by hand at the end of a shift or day, so "real time" can mean "next morning."
• One Excel workbook may belong to one person, with its own column names and definitions.
• Older machines may have no network connection, so cycle counts and downtime are written down rather than collected. See retrofit machine monitoring on older Japanese machines.
• An in-house system may depend on a few people who know how it works, so changes to export formats can take time.

None of this means the data is poor. It means you should ask how each item is created before you build reports or contracts around it.

Large Companies and the SAP 2027 Deadline

At large Japanese companies, replacing old ERP is a major topic. In 2020, SAP announced that mainstream maintenance for SAP ERP 6.0 would run to the end of 2027, with extended maintenance at extra cost available to the end of 2030. Many companies are studying a move to newer products or to the cloud ahead of that deadline, often called the "2027 problem" in Japan. If a Japanese customer or parent company is in the middle of such a migration, ask whether interfaces, part number formats, or EDI timing will change, and when.

Assembly vs. Process Plants

What a plant asks of its systems depends on the industry. Assembly manufacturers such as automotive and electronics combine many parts, so they focus on material ordering from the bill of materials (BOM), progress tracking by process, and history by product serial number. Process manufacturers such as chemicals, food, and pharmaceuticals blend raw materials and run reactions or heating, so they focus on recipe management, recording conditions such as temperature and pressure, and tracing raw material lots to product lots. MES products range from general-purpose packages to products built for specific industries such as semiconductors, pharmaceuticals, food, and auto parts. In pharmaceuticals and other industries with strict rules on production records, plants commonly use MES products with features for those regulations.

What Plants Expect from MES and ERP

Knowing why a Japanese plant invested in these systems helps you understand which data it trusts. ERP brings data that used to sit in separate departments into one place, so management can see the business faster and more accurately, and staff spend less time collecting spreadsheets from each department to reconcile at month-end. MES makes the floor visible in real time: progress and defects that used to live in paper daily reports and on whiteboards become data, so the plant can see where delays or defects occur. When MES gives operators the work steps and inspection items, it also reduces quality variation between operators.

Linking ERP and MES shows the gap between plan and actual results sooner, which improves plan revisions and the accuracy of delivery-date answers. The accumulated data supports improvement work, predictive maintenance, and wider data use. Machine data alone is not enough, though. It becomes useful for quality analysis or costing only when it is tied to a product, a lot, and a process, and MES is the system that holds that link.

Why These Projects Often Struggle

MES and ERP projects take months to years and include reworking business processes, not just buying software. A typical project runs from assessing current work and systems, setting goals and scope, and choosing a product, through requirements and design, data preparation and testing, to go-live, training, and checking results. Many companies start with one line or one function, such as traceability or progress visibility, and expand once it works. Even so, these projects often run into trouble. Commonly cited reasons:

• The goal becomes "install the system," and the problem to solve stays vague.
• Custom add-ons pile up to match existing work practices, so costs rise and upgrades get harder.
• Master data, such as items, BOMs, and routings, is incomplete or wrong, so results are wrong.
• Data entry is a burden on the floor, people stop entering data, and the system becomes a formality.
• Older machines cannot connect to the network, so results cannot be collected automatically.

A system can do nothing beyond the data it receives. If the BOM or routing does not match reality, both the plan and the cost will be wrong. A system also cannot fix an inefficient process; companies usually rework the process first and then put it into the system. Products and processes change over time, so settings need regular review, and without people to maintain them the system drifts away from what actually happens on the floor within a few years.

These points matter when you request data. If an answer is slow or inconsistent, the cause is often master data or manual entry, not unwillingness to share.

Exchanging Data with a Japanese Plant: What to Check

Whether you are a customer asking a Japanese supplier for traceability data, an overseas plant connecting to a Japanese parent's system, or a supplier receiving forecasts, the same questions come up. The table below lists the items to confirm before you agree on a format or an interface.

Item	What to confirm	Why it matters
System of record	Which system (ERP, MES, production management system, or spreadsheet) owns each data item	Two systems can show different inventory or results for the same item
System and version	Product name, version, and whether it is a package, in-house build, or Excel	Sets what export formats and interfaces are realistic
Part numbers	How your part numbers map to the plant's internal part numbers (hinban, 品番), including revision levels	Mismatched codes are a common cause of failed imports
Lot and serial numbers	Format, who assigns them, and how material lots link to product lots	Traceability depends on this link
Units and quantities	Units of measure, pack quantities, and how scrap and rework are counted	Quantities can be off by a pack multiple without anyone noticing
Timing	Real time, per shift, daily batch, or monthly; and when data is entered by hand	"Latest" data may be a day or more old
Dates and time zone	Date format, time zone (Japan uses JST, UTC+9), and month-end cutoff dates	Shifts and cutoffs may fall on different dates for you and the plant
File format and encoding	CSV, Excel, EDI, or API; character encoding (Shift_JIS or UTF-8)	Japanese text can turn into garbled characters if the encoding is wrong
Field definitions	Exact meaning of fields such as "completed," "good parts," and "utilization"	Japanese and overseas plants may use different definitions
Owner and contact	Who maintains the system and who approves format changes (production control, IT department, or an outside system integrator)	Format changes can stall without the right approver

On encoding: Excel on Japanese Windows typically opens CSV files as Shift_JIS by default, so a UTF-8 file can display Japanese text as garbled characters (mojibake), and a Shift_JIS file can do the same on your side. Agree on the encoding in writing, and test with a file that contains Japanese item names.

Questions to Ask the Japanese Side

• Which system holds this data today: ERP, MES, the production management system, or a spreadsheet?
• What is the product name and version, and is it installed on-site or in the cloud?
• Is this item collected automatically from equipment, or entered by hand? When is it entered?
• Which system's inventory figure do you treat as correct?
• How do your internal part numbers and lot numbers relate to ours?
• Can you export this as CSV in UTF-8, and if not, which encoding will you use?
• Are there any planned system changes (for example, an ERP migration) that will change the format or timing?
• Who should we contact for technical questions about the data, and who approves changes?

To find the right department, see Japanese factory departments: who is who. When an outside system integrator (often called an "SIer" in Japan) maintains the system, see how makers, distributors, and SIers fit together.

Email Template: Requesting Production Data

Short, numbered questions are easier to forward inside a Japanese company and easier to answer in writing. Adjust the items to your case.

Subject: Request for lot traceability data – [Part number] – [Your company]

Dear [Name],

We would like to receive lot traceability data for [part number] on a regular basis, starting from [month]. Before we set up the format, could you answer the following questions?

1. Which system holds this data today (ERP, MES, production management system, or Excel)?
2. Is the data entered automatically or by hand, and when is it updated?
3. Can you send it as a CSV file in UTF-8? If not, please tell us the encoding.
4. How do your lot numbers link material lots to finished product lots?
5. Who should we contact for questions about the data?

We have attached a sample of the format we would like. If another format is easier for your system, please let us know and we will adjust.

Best regards,
[Your name]
[Company, department]

If the request is for quality records after a defect, route it through the quality assurance contact as well; see the quality assurance process at Japanese plants.

Limits of This Guide

• The split between ERP, MES, and production management systems differs by company, product, and industry. The descriptions here are typical patterns, not rules.
• The package names and shares come from one 2024 survey of Japanese companies with annual sales under JPY 50 billion. They do not describe large companies or overseas subsidiaries.
• How widely plants use in-house systems, Excel, or paper is not measured here. Ask each plant how its data is produced.
• SAP maintenance terms can change. Confirm current dates and options with SAP or your vendor.
• This guide does not cover data security, contracts, or legal requirements for sharing production data across borders.

FAQ

What Is the Difference Between MES and ERP?

ERP plans and manages the whole business, including accounting, sales, purchasing, and inventory, on a monthly, weekly, or daily scale. MES runs and records production on the shop floor, by the hour, minute, or second. In ISA-95, ERP is Level 4 and MES is Level 3.

What Is a Production Management System in Japan?

A seisan kanri shisutemu usually covers orders, production planning, material ordering, process control, inventory, and cost. It often combines parts of ERP and MES, and many small and mid-sized Japanese manufacturers run their plants on one such system.

How Do MES and ERP Integrate?

ERP sends the production plan down to MES, and MES sends production results back up to ERP. ISA-95 (IEC 62264) defines the boundary between them. In practice, the key decisions are which system holds detailed schedules and inventory, and which one is the system of record.

Why Did My Japanese Supplier Send Data in Excel Instead of from Its MES?

Many Japanese plants cover MES-type functions with in-house systems, spreadsheets, and paper rather than an MES product, and some data is entered by hand. Ask where each item comes from and how often it is updated before you rely on it.

Sources

• ERP definition: Oracle, "What Is ERP?" (Japanese)
• ERP history (MRP, MRP II, Gartner 1990): NetSuite, "ERP History"
• MES definition and MESA-11 functions: Fuji Electric, "What Is MES (Manufacturing Execution System)?" (Japanese)
• MESA-11 functions and history: Tulip, "MES, ISA-95, MESA-11, c-MES, and NAMUR"
• ISA-95 levels: Siemens, "ISA-95 Framework and Layers" (Japanese)
• IEC 62264-1 editions and scope: ISO, "IEC 62264-1:2013 Enterprise-control system integration — Part 1: Models and terminology"; IEC Webstore, IEC 62264-1
• ERP and MES time scales: MES Magazine, "What Are MES and ISA-95?" (Japanese)
• Production management packages and operation forms at Japanese SMEs: Nork Research, 2024 press release on production management systems for SMEs (Japanese)
• SAP ERP 6.0 maintenance dates: Cloud Watch, "SAP extends SAP ERP maintenance to end of 2027" (February 5, 2020, Japanese); SAPinsider, "SAP Announces Extension of Mainstream Maintenance for SAP ERP 6.0"
• Excel and Shift_JIS CSV files: OutSystems forum, "Downloaded CSV file: the Japanese characters are garbled"