PROCESS

Here is How to Build

Design

Sub

The parts make the whole

This volume began with a claim: a large process is built of sub-processes, and the designer's work is to cut it into the right parts, each whole, each in its place, each doing its piece, combined back into a process that holds. The disciplines since then have taken that claim apart and looked at each piece of it in turn. What a sub-process is. When a piece should be one, and when it should stay a step. How to cut it clean. Where to place it. What result it answers for. How to join it to its neighbours. And how to keep it clean as the work drifts. Here, at the end, they come back together.

Seen together, they are not seven separate skills. They are faces of a single act: making parts that add up to a process that holds. The parts are the sub-processes this volume has been about, together with the steps that rightly stay steps. A clean cut matters because a part with ragged edges cannot be placed, owned or joined. A good place matters because a clean part in the wrong position still breaks the flow. A clear result matters because it is what the neighbours rely on and what the whole is made of. A thin seam matters because it lets each part stay free while the whole stays joined. And watching for drift matters because all of it was true of the work as it was, and the work keeps moving.

So no part is good on its own. A sub-process is good for the whole it serves: it is cut where the whole divides naturally, placed where the whole needs it, answering for a piece of the whole's result, joined so the whole holds. Judge a part by itself, and a beautifully drawn sub-process can still be the wrong one. Judge it by what it does for the whole, and every discipline in this volume becomes a question you can ask of it: is it clean, is it in the right place, does its result fit, does its seam carry only that result, is it still true to the work?

The highest possible standard is to see every discipline of this volume as one act, making parts that combine into a process that holds, and to judge every sub-process not by itself but by what it does for the whole: cut clean, placed by need, answering for its piece of the result, joined at a thin seam, and kept true as the work moves.

Key Takeaway: The volume's disciplines (what a sub-process is, sub or step, cutting clean, place, function, the seams within, drift) are not separate skills but faces of one act: making parts that add up to a process that holds. The parts are the sub-processes, together with the steps that rightly stay steps. Each discipline matters because of the whole: a clean cut can be placed and owned, a good place keeps the flow, a clear result is what the neighbours rely on, a thin seam keeps the parts free and the whole joined, and watching for drift keeps all of it true. No part is good on its own; judge each one by what it does for the whole.

Every discipline in this volume is one act: making parts that combine into a process that holds; judge each sub-process by what it does for the whole.

MarvinPro · PROCESS · Here is How to Build · Design · Sub · Discipline 8: Sub-Processes · Section: The parts make the whole

MarvinPro | October 2026

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No more sub-processes than the work needs

If the parts exist for the whole, then the number of them matters too. And the default is fewer. Every sub-process you name has a cost: a name to keep true, a result to state, an owner to give it, seams to design on both sides, a place on the map that everyone who runs the process has to carry in their head. A process with more sub-processes than its work needs pays those costs for nothing, and worse, the extra parts bury the real shape of the work under divisions that mean nothing.

So start from as few sub-processes as possible, and add one only when a piece earns it. The signs are the ones from the second discipline: the piece has a real flow of several acts; it can fail halfway and the handling matters; it is owned or performed by a distinct team within the process; it is reused in more than one place; or it is worth working on, owning or walling off on its own. If a piece shows none of these, it stays a step, however important it feels. The burden of proof is on adding a part, not on leaving one out.

That does not make too few a virtue. A real flow left inside a single step is still a hidden structure, its failures undesigned, waiting to surface as something nobody planned for. The aim is not the smallest possible number but the honest one: every sub-process the work truly has, and not one more. And because the work moves, that number moves too. Drift adds parts quietly, and a design that once had the right number can, years later, carry several that no longer earn their place. So the count is checked like everything else, and merges and retirements are as much a part of good design as splits.

The highest possible standard is to keep the number of sub-processes as low as the work allows, starting from as few as possible and adding a part only when a piece earns it by the signs (a real flow, failure that matters, a distinct owner, reuse, or a need to work on it alone), never leaving a real flow hidden in a step, and checking the count as the work moves so that parts which no longer earn their place are merged or retired.

Key Takeaway: Every sub-process has a cost: a name, a result, an owner, seams on both sides, a place on everyone's map. Extra parts pay that cost for nothing and bury the real shape of the work. So the default is fewer: start from as few sub-processes as possible, and add one only when a piece earns it by the signs from the second discipline (a real flow, failure that matters, a distinct owner, reuse, a need to work on it alone). The burden of proof is on adding a part. Too few is still a failure (a real flow hidden in a step), so the aim is the honest number, checked again as the work drifts.

Start from as few sub-processes as possible, and add one only when a piece earns its place; the burden of proof is on adding a part.

MarvinPro · PROCESS · Here is How to Build · Design · Sub · Discipline 8: Sub-Processes · Section: No more sub-processes than the work needs

MarvinPro | October 2026

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Every sub-process is someone's whole

There is one more way to look at a sub-process, and it is the one this volume opened with. From the designer of the larger process, a sub-process is one part: a name, a place, a result, two seams. But a sub-process is usually owned by someone: a team or a department that does that piece of work every day. And from where they stand, it is not a part at all. It is their whole job, start to finish. It has its own beginning, where work arrives from the part before; its own end, where its result goes on to the part after; its own result to answer for; and, very often, its own parts inside. For the team that owns it, a sub-process is their end to end.

This is the relativity met throughout this book: the company's core turned out to be, from a wider frame, a support process, and a department's core a sub of the company's core. The same holds all the way down. So the owner of a sub-process designs it as a whole, with everything this volume teaches: they cut it into its own parts, place them, give each a result, join them at clean seams, and watch them drift. Meanwhile the designer of the larger process sees one part and relies on one thing only: its result. Both views are true, and neither is complete without the other.

The process holds when both are kept. The owner keeps the result the larger process relies on, and is free to change anything inside as long as it holds, which is the freedom the fifth discipline described. The designer above keeps the seams clean and leaves the inside to its owner, which is what makes that freedom real. When the owner forgets the whole around them, their part starts to drift away from what its neighbours need. When the designer above forgets that every part is someone's whole, they start reaching inside parts they should leave alone. Keep both, and the same disciplines run at every level, inside each part and around each whole, down to the steps themselves, where the next volume of this book begins.

The highest possible standard is to see every sub-process both as one part of the larger process and as a whole to the team that owns it, letting the owner design it with all the disciplines of this volume and answer for its result, while the designer above relies only on that result and keeps the seams clean, so the same disciplines hold at every level of the process.

Key Takeaway: From the designer above, a sub-process is one part; from the team that owns it, it is their whole job, their end to end, with its own start, finish, result and often its own parts. This is the book's relativity again: the company's core turned out to be, from a wider frame, a support process, and a department's core a sub of the company's core. So the owner designs it as a whole, with every discipline of this volume, and answers for its result; the designer above relies only on that result and keeps the seams clean. Both views are true, and the process holds when both are kept.

Every sub-process is one part to the designer above and a whole to the team that owns it; the process holds when both views are kept.

MarvinPro · PROCESS · Here is How to Build · Design · Sub · Discipline 8: Sub-Processes · Section: Every sub-process is someone's whole

MarvinPro | October 2026

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A real example

Return to activate one last time, and see settling the payment from both sides. From activate, it is one part. It has one name and one result: a payment settled, or declined and the customer told. It sits first, because nothing else in activation can begin without it. Its seam to opening the account (since the seventh discipline, one part with recording the entitlement) carries only that result, with the customer and plan the account needs, and it has a defined way back if the account cannot be opened. That is all activate needs to know about it, and all it should know.

Now stand where the payments team stands. For them, settling the payment is not one part; it is their whole. It begins when activate hands them a subscription to settle, and ends when they hand back that one result. Inside, it has its own parts: since the split in the seventh discipline, card and wallet payments, bank transfers and instalments, each with its own result, joined at seams of their own, and reaching the finance process for the charge as a connection, not a part. The team designs those parts with exactly the same disciplines this volume taught for activate. And they keep their count honest: card and wallet stay together, because they settle and fail the same way, and splitting them would add a part that earns nothing.

Both views hold at once. The payments team can change how retries work, add a new payment method at the right joint, or merge two of its parts, without asking activate, because activate relies only on the result. And activate can be redesigned around settling without anyone touching its inside. Step back one more level, and the same is true again: activate itself is one of four parts of the subscription core, and the subscription core one part of the company. At every level, the parts are someone's whole, and the whole is made of parts. That is what it means for a process to be built of sub-processes.

Settling the payment is one part of activate, answering for one result, and at the same time the payments team's whole, with its own parts, seams and drift; both views hold, at every level of the process.

MarvinPro · PROCESS · Here is How to Build · Design · Sub · Discipline 8: Sub-Processes · A real example

MarvinPro | October 2026

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Sub-Processes

The disciplines of this volume are faces of one act: making parts that combine into a process that holds. What a sub-process is, sub or step, cutting clean, place, function, the seams within and drift each answer one question about a part, and every answer is judged by the whole. The parts are the sub-processes, together with the steps that rightly stay steps, and no part is good on its own: it is good for the whole it serves.

The number of parts matters too, and the default is fewer. Every sub-process carries a cost: a name, a result, an owner, seams, a place on everyone's map. So start from as few as possible, and add one only when a piece earns it by the signs (a real flow, failure that matters, a distinct owner, reuse, a need to work on it alone). The burden of proof is on adding a part. Too few is still a failure, but the aim is the honest number: every sub-process the work truly has, and not one more, checked again as the work drifts.

And every sub-process is someone's whole. To the designer above, it is one part with one result; to the team that owns it, it is their whole job, start to finish, with its own parts inside. The owner designs it with every discipline of this volume and answers for its result; the designer above relies only on that result and keeps the seams clean. Both views are true, and the process holds when both are kept, at every level from the company down to the steps.

So the discipline of this volume, taken whole, is this: build a large process of sub-processes, as few as the work allows and each one earning its place; cut each clean, place it by need, give it one result to answer for, and join it at seams that carry only that result; watch the parts as the work moves, and re-cut when the signs are clear; and remember that every part is someone's whole. Done this way, a process too large to hold in one piece becomes a set of parts that anyone can find, own, change and trust, and that together hold as one process.

A large process is built of sub-processes: as few as the work allows, each cut clean, placed, answering for its result and joined at clean seams, and each one someone's whole.

MarvinPro · PROCESS · Here is How to Build · Design · Sub · Discipline 8: Sub-Processes · Chapter Outcome

MarvinPro | October 2026

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