A roadmap for digitalizing Excel and fax workflows — lessons from a legacy-industry DX

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 the path to systematizing a front line where phone, fax, and Excel play the leading roles.

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. 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.

3. 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.

4. 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.

5. 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

6. 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.

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.

7. 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.