When Excel hits its limits: how to move off spreadsheets — choosing what to migrate to (SaaS, kintone, custom build) and digitizing fax orders in stages

The conclusion first. The one path that does not fail at digitalizing work run on Excel, fax, and phone is to proceed not by "replacing everything with a system all at once" but in the order "business inventory → prioritization → phased systematization." Before you consider which system to buy or build, first write out on a single sheet "who is now doing what, by what means, how often, and whether a record is kept." Work backward from this and the order in which to invest becomes visible naturally. This article is a practical roadmap that, weaving in a Minister of Economy, Trade and Industry Award-winning lumber-distribution DX case (anonymized), concretely explains from a buyer's perspective how to systematize a front line where phone, fax, and Excel play the leading roles — from telling whether Excel management has hit its limits, through the inventory → prioritization → phased-systematization roadmap and choosing what to migrate to (off-the-shelf SaaS, no-code tools such as kintone, a custom build, or a hybrid), to digitizing order intake while trading partners keep faxing.

1. Why "Excel, fax, and phone" generate invisible costs

The first thing to recognize is the fact that analog work is "running, yet quietly hemorrhaging costs." Because no visible failure occurs, it tends to be put off, but losses like the following pile up daily.

The "Cliff of 2025" that METI warned about in its "DX Report"—the problem that failing to renew aging, black-boxed systems could cause large economic losses—is not a single deadline but "a valley that grows deeper the longer you defer." Before the people who know the internals retire, there is value in at least starting from the inventory. The full picture, including how to think about cost and public support, is covered in detail in the buyer's guide to crossing the "Cliff of 2025". This article narrows its focus to what comes before that: "from where, and in what order, do you begin."

The perspective a buyer should hold first: digitalization is done not to "make things convenient" but to "crush invisible costs and key-person risk." So it is rational to begin with the most painful work.

2. Signs that Excel management has hit its limits — a checklist

Excel is an excellent tool, and there is no need to replace all of it. The trouble starts when Excel is made to carry the role of a business system rather than a spreadsheet. Hold your own work up against the following signs.

Signs of effort (sometimes reducible with better habits)

• "Which one is the latest?" comes up often (file names collect "latest," "final," "v3")
• The same data is typed in twice or more (transcribing fax → Excel, Excel → accounting software)
• Month-end or week-end totals mean matching several files against each other by hand
• Files are slow to open or save, and you have had to scramble to recover a broken one

Structural signs (time to consider replacing Excel, not improving it)

• What each trading partner or department is allowed to see is separated by splitting or copying files
• Only the person who built the macros (VBA) or formulas can fix them
• Orders received by fax or phone leave no record (or only a paper copy)
• Staff on site or on the road can't check or enter inventory and progress on the spot, so they confirm by phone or fax
• You can't trace who changed what and when, so you can't pin down the cause of a mistake

The trick is to judge by which kind of sign, not by how many apply. If you only see signs of effort, rethinking how files are shared can be enough. Structural signs are caused not by how Excel is used but by a setup that relies on "files and people's memory" for records, permissions, and handovers — so every workaround tends to deepen the dependence on particular people. If even one structural sign shows, it is time to use the roadmap from the next chapter to decide which work to replace first.

If you'd like to work out for yourself where to start, use the DX self-assessment worksheet (25 checks, free). Moving through inventory → priority scoring → "off-the-shelf SaaS or custom build" → cost-effectiveness → funding, you end up able to state, in your own words, the first process to fix and the most you should spend on it. To have your answers sanity-checked, book the free 30-minute DX assessment and we'll go through them together. It's free with no sales pitch, and afterwards I send an assessment memo with priorities, a rough cost range, and recommended steps.

3. The overall picture of the roadmap

Digitalization runs through the following three steps in order. The key is to decide each step's deliverable (output) in advance.

STEP 1  業務の棚卸し        → 現状の業務一覧表（誰が・何を・どう・頻度・記録）
   ↓
STEP 2  優先度付け          → 着手順マトリクス（痛み × 実現容易性）
   ↓
STEP 3  段階的システム化    → 可視化 → 部分自動化 → 全面移行
        （各段で現場が便益を実感してから次へ）

A common failure is skipping STEPs 1 and 2 and abruptly bracing for something big like "replacing the core system." The bigger you brace, the more requirements swell, costs jump, and the front line gets left behind. Conversely, if you pick one high-pain task and start by lightly visualizing just that, the front line gains the felt sense that "this is convenient," and you win cooperation for the next investment.

4. STEP 1 — Business inventory (how to build the inventory)

Before considering systems, first put the current state on paper (or a spreadsheet). Don't overthink it—just filling in the following five-column table is enough.

There are three tips for the inventory.

1. Write the "actual state," not the "ideal" — write out the procedures the front line actually performs (including workarounds and exception handling), not what the manual says. The real bottlenecks lurk here.
2. Weight the "is a record kept?" column most heavily — work that leaves no record (phone, fax, verbal) will invariably become kindling for trouble later. The first purpose of digitalization is to fill this "record blank."
3. Write the connections (before and after) too — work is chained, as in "order intake → inventory check → quote → order." Even if you carve out just one and systematize it, if what comes before and after stays on paper, you only increase double entry. Grasp it in units of the chain.

This inventory table itself becomes the foundation of the requirements definition when you place your order. Rather than throwing it to a vendor with "just DX it nicely for us," whether you can show this table and say "we want to crush this red-lettered (record ×) work first" makes a big difference to both the accuracy of the quote and the adoption rate.

5. STEP 2 — Prioritization (where to begin)

Once the inventory is done, don't try to do everything at once. Evaluate each task on the following two axes and decide the order to begin.

• Vertical axis: size of the pain — the severity of "troubles" such as no record kept / checks take time / many errors / dependent on individuals.
• Horizontal axis: ease of realization — whether existing tools can handle it, whether the work is simple, whether there are few stakeholders.

        実現：難しい            実現：容易
      ┌───────────────┬───────────────┐
痛み  │  ② 中期で計画   │  ① 最優先      │
大    │ （分割して着手）│ （まずここ）    │
      ├───────────────┼───────────────┤
痛み  │  ④ 当面やらない │  ③ 余力で       │
小    │               │ （小さな改善）  │
      └───────────────┴───────────────┘

The trap a buyer easily falls into here is starting from ③ solely because "it's easy to build." That leaves the front line's biggest pain in place and earns the verdict "we put in a system but it didn't get easier." Always choose the first project from ① (large pain, easy to build). Solving the single point the whole company struggles with most first makes the front line your ally and gets the subsequent budget approved more easily. The decision axes for the technical side—"which technology to choose"—are summarized in the technology-selection framework for legacy-industry DX.

6. STEP 3 — Phased systematization (three phases)

Once priority is set, proceed with the chosen work not by fully automating it all at once, but in three stages. The iron rule is to advance to the next only after the front line feels the benefit at each stage.

Phase A: visualization (first make it "visible")

Before automation, simply gathering scattered information into one place so it can be seen yields half the benefit. Consolidate orders received by fax and phone into a simple input form. Turn inventory scattered across everyone's Excel into a shared list. At this stage, judgment and processing remain human. Just "a record is kept" and "you know the latest version" drastically cut the back-and-forth of confirmation. The barrier to adoption is lowest here, so this is where you earn the front line's trust.

Phase B: partial automation (hand repetitive work to the machine)

On top of the visualized data, automate only the repetitive work that has clear rules. Automatic quote calculation, automatic inventory allocation, automatic generation of business documents (invoices, delivery slips), and so on. What's important here is not trying to automate everything. Always leave "room to override manually" so humans can judge the exceptions. Aim for full automation and development costs balloon handling rare exceptions, which ends up binding the front line instead.

Phase C: full migration (wind down the old flow)

Only after the new way has taken hold and the front line feels "we can't go back," do you formally retire the old flow (fax, paper) for the first time. Only when you reach this point does double entry disappear and the investment enter its payback phase. Stopping the old flow too early in haste ties migration trouble directly to a work stoppage, so it is safest to secure an ample period of parallel operation.

[A 可視化]  記録が残る・最新が分かる      … 定着の土台（低リスク）
    ↓  現場が便益を実感したら
[B 部分自動化]  ルール化できる作業を機械へ  … 例外は人が上書き可能
    ↓  新フローが日常になったら
[C 全面移行]  旧フローを畳む・二重入力ゼロ  … 投資回収フェーズ

7. What to replace it with — four places to migrate off Excel (off-the-shelf SaaS, kintone, custom build, hybrid)

Once the high-priority work is decided, the next question is what to replace Excel with. There are broadly four options, and the choice is not about which is best but about how unique that work is to your company. Migrating a ledger built in Access follows the same four-way choice.

The order of judgment matches the "choosing the remedy" part of the DX self-assessment worksheet. First ask whether the work is common across your industry; if it is, actually try at least one off-the-shelf SaaS on a free trial. If a company-specific part remains, split no-code from custom build by asking whether it is enough to share and fill in the Excel table, or whether cross-company permissions and complex rules are the core. For a sense of development costs, see the complete guide to commissioning system development.

What to check when considering kintone

kintone often comes up as a place to move off Excel. To avoid "this isn't what I expected" after rollout, check the following on the official pricing page (Japanese; accessed 3 October 2026; prices exclude tax).

• Courses and monthly price: Light course ¥1,000, Standard course ¥1,800, Wide course ¥3,000 (all per user). There is no initial fee, and a 30-day free trial is available.
• Minimum users: 10 users for Light and Standard, 1,000 users for Wide. Even a company with three users contracts for 10 users on Light or Standard (on Standard, 10 users × ¥1,800 means from ¥18,000 a month).
• Extensions require Standard or above: data integration with external services (API), plug-ins, and customization with JavaScript or CSS are not available on the Light course. If you plan to connect it automatically to accounting software or other systems through the API, Standard or above is a given.
• Limits: up to 200 apps on Light, 1,000 on Standard, and 3,000 on Wide. API requests per app are 10,000 a day on Standard and 100,000 a day on Wide.
• Users outside the company: guest users, a paid option, are provided as a way for trading partners and other outsiders to use it.

The greatest strength of no-code is that the people doing the work can change it themselves. Flip that around, and the more plug-ins, JavaScript customization, and external integrations you layer on, the more that strength fades — and the dependence on whoever wrote the customization returns. When extensions become the center of the work, that is a sign to consider a custom build or a hybrid. Conversely, for work where sharing and filling in an Excel-style table is enough, there's no need to start with a custom build.

8. Digitizing fax orders in stages — while trading partners keep faxing

When you decide you want to stop taking orders by fax, the first thing you run into is not technology but your trading partners. Each has its own ways and circumstances, and you can't make them give up fax for your convenience alone. Push a switch on them and you may lose the orders themselves.

So turn the idea around: leave your partners' ways alone and change your own intake. The principle is "many entrances, one record."

Three points matter.

• Stage ① alone solves "no record is kept." The heart of the pain in fax orders is not the typing but "he said, she said" and the back-and-forth of confirmation. Once every order lands in the order list with a record, whatever channel it came through, that pain disappears without anything changing for your partners. This corresponds to Phase A (visualization) in Chapter 6.
• Don't aim for full automation at stage ②. How accurately data can be read varies with the form's format and whether it is handwritten. Keep a human check as a given, and automate only as far as it makes the check easier (the same thinking as Phase B).
• Run ③ and ④ at your partners' pace. A new way to order is something you offer as convenient, not something you impose. If you wait for fax's share to fall before shrinking it, you won't drop orders (this corresponds to Phase C).

In the lumber-distribution DX in the next chapter, too, one of the starting problems was that "fax orders left no record, and confirming by phone took hours every day."

9. A real example: a legacy-industry DX with a multi-stage trade flow and permission separation

Let me apply this roadmap to an actual lumber-distribution DX (anonymized). In this industry, phone, fax, and Excel were the mainstream: inventory in Excel, ordering by fax leaving no record, and checking work requiring several hours every day—a textbook "ultra-legacy industry."

The hard part is that the trade flow is multi-stage and there are many players. Roughly written, the flow looks like this.

林業 → 市場 → 製材所 → プレカット → 工務店
                 ↓
             メーカー → 問屋 → その他

For each player, "what they can do," "the information they should see," and "how prices are handled" are entirely different. The market wants to see the whole inventory, but a sawmill wants to see only its own and its trading partners' inventory. A construction firm may place orders but must not see other companies' purchase prices. In other words, the core of this industry's DX was, more than the features themselves, the permission design of "who is shown which information and what they're allowed to operate."

Here, this article's roadmap works exactly as is.

• In the inventory (STEP 1), we first enumerated, per player, "what / by what means / is a record kept," and visualized the flow of information and the boundaries of permissions.
• In prioritization (STEP 2), we placed the highest-pain "turning fax orders into records" and "centralized inventory visualization" at ① top priority.
• In phased systematization (STEP 3), we first made inventory and order intake/placement visible (Phase A), and on that basis moved to partial automation of quote calculation and business-document generation (Phase B). For the documents, we adopted an Excel-based generation approach so as not to disrupt the familiar Excel look the front line was accustomed to.

Technically, we implemented this permission separation with a scheme that explicitly enumerates, on the server side, the operations allowed for each business type (a design that holds an allowlist at the router layer), structured so that permissions never leak due to the front end's convenience. Many stakeholders use the same screens while the visible range is strictly divided—because bolting on this "information separation per tenant (stakeholder)" later makes rework costs skyrocket, enumerating the permission boundaries at the inventory stage and including them in the very first design decision greatly governed long-term maintainability. This way of thinking applies regardless of industry; multi-tenant SaaS data isolation and authorization design and an architecture deep dive into the award-winning B2B SaaS cover the technical details.

Before / after (only facts stated in the case study)

The design and technical decisions are written up in detail in the lumber-distribution DX case study.

Note that this product won the Minister of Economy, Trade and Industry Award, but that is an external evaluation, and I will not speak definitively in this article about business-outcome figures such as revenue or the number of companies using it (those belong to the client's real data). What can be said for certain here is that keeping to the order "inventory → prioritization → phased rollout" was one of the reasons the system took hold at an ultra-legacy front line.

10. What to decide before placing an order

Finally, here is a checklist for translating this roadmap into an order to a vendor.

A buyer who can say "not 'handle it all nicely,' but 'starting from this red-lettered work, in this order'" gets an entirely different accuracy of quote and post-completion adoption rate. Digitalization is not a one-time major construction project but a continuous effort of crushing tasks one at a time in order of pain. First, start by writing out one task—the one you're struggling with most right now—from your head into a table. That is the first step of a DX that does not fail.

If you're unsure how to write it out, start by filling in the DX self-assessment worksheet (25 checks, free) in order. To check what you've written, we can go through it together in the free 30-minute DX assessment.