Compared to commercial platforms¶
An organization choosing whether to build its workflows on Orchestra often weighs it against a commercial platform it already has or could buy. This page compares Orchestra with two of them, feature by feature:
- Microsoft Power Automate, its cloud flows: what an organization on Microsoft 365 uses for approvals and automation.
- Appian, a low-code process automation suite, named a Leader in Gartner's first Magic Quadrant for business orchestration and automation (October 2025).
Pega, Bizagi and ServiceNow are covered at the end, in less detail: Other platforms says why. For the open source engines, see Compared to other BPM engines.
Read this page as a map, not a verdict
Each product cell says what the vendor's public documentation says, linked. The page compares documented features only: it is not a benchmark, and no product was used to write it. The cells were checked in November 2026. Commercial products change often, and a feature can depend on the edition or the license: before choosing, check the point that matters to you in the vendor's current documentation. "Not found" means the vendor's documentation did not show it when it was searched, not that the product cannot do it.
At a glance¶
Orchestra's cells link to the page that explains each feature. Their color says where Orchestra stands:
| Color | Means |
|---|---|
| Yes | Orchestra does it. |
| Partly | Orchestra does part of it, or does it another way. |
| Not yet | An issue is open for it. |
| No | Orchestra does not do it, and nothing is planned. |
Modeling¶
| Feature | Orchestra | Power Automate | Appian |
|---|---|---|---|
| Graphical modeler | Yes: a BPMN.io canvas, and a form-based modeler for people who do not use a canvas (Integrations) | Yes: the flow designer (designers) | Yes: the process modeler (process modeling) |
| Work in any order, as a case | Partly: a case is a workflow whose handlers wait for conditions, each item offered while its condition holds; there is no stage or milestone (Running a workflow as a case) | Not found. Business process flows, which guide a record through stages, are a premium feature (licensing) | Yes: Case Management Studio, preinstalled on new Appian Cloud sites (Case Management Studio) |
Flow control¶
| Feature | Orchestra | Power Automate | Appian |
|---|---|---|---|
| Exclusive and parallel choice, and joining branches | Yes, as a split and a join on any step, inclusive choices included (Joins and splits) | Yes: conditions, and parallel branches; an action set to run after the last action of each branch joins them (parallel approvals, joins) | Yes: AND and XOR gateways (process nodes) |
| One branch per item of a list, all at once or one after another | Yes: the per_item and per_member splits (One branch per item) |
Yes: Apply to each, one item after another by default, up to 50 at once when set to (parallel execution) | Yes: multiple node instances, run all at once or one at a time (looping) |
| Going on when N of M people have answered, or when a vote is decided | Yes: the threshold and quorum joins, which cancel the late branches (Joins and splits) |
Partly: an approval waits for everyone, or for the first answer (approvals) | Yes: a subprocess run for many instances goes on when the first, all, or n of them are done (node properties) |
| A called workflow | Yes: run as a separate instance or inside the parent, pinned to a child version (Subprocesses) | Yes: a child flow (parallel execution) | Yes: a subprocess, or a process started by the Start Process smart service, waiting for it or not (start process) |
Work done by people¶
| Feature | Orchestra | Power Automate | Appian |
|---|---|---|---|
| Handing a task to someone else | Yes: reassignment, and delegation for an absence period (Delegation) | Partly: an approver can reassign; delegation needs the Approvals Kit, in preview (approvals) | Yes: a task can be reassigned, except in an autoscaled process (node properties) |
| Reminding, then escalating to a manager | Yes: a ladder of timers on the step, with no code (Timers) | Not found | Yes: escalation timers, each level started when the one before fires, which can reassign the task (node properties) |
| A task waiting weeks or months | Yes: an instance runs for as long as it needs (Concepts) | No: a run lasts 30 days at most, and an approval waits 28; a longer wait splits the work into two flows (limits, approvals) | No limit found; Appian advises archiving completed processes, after 7 days by default, to free memory (archiving) |
Decisions, events and time¶
| Feature | Orchestra | Power Automate | Appian |
|---|---|---|---|
| Decision tables | Partly: in Orchestra's own format, not DMN, with the first-match and collect hit policies (Decision tables) | Not found | Yes: decisions, with DMN hit policies (decisions) |
| Waiting for a message addressed to one instance | Yes: by correlation key or variable values (Waiting for an event) | Not found | Yes: a Receive Message event, which acts on the messages its conditions accept (receive message) |
| A message for every instance waiting for it | Yes: a broadcast event (Deliver, or broadcast) | Not found | Yes: a Send Message event reaches every Receive Message event listening (send message) |
| Working time: working hours and closed days | Yes: working calendars, with holidays that follow Easter (Working calendars) | Not found | Yes: a process calendar timers can count with, configured in each environment (process calendar) |
| Undoing completed steps (compensation) | Not yet: #3634775, postponed | Not found | Not found |
Running workflows¶
| Feature | Orchestra | Power Automate | Appian |
|---|---|---|---|
| A running instance keeps the version it started on | Yes (Versioning) | Not found: flows have draft and published versions; the documentation does not say what a run already going does when a new version is published (versioning) | Yes (process upgrade) |
| Moving running instances to a newer version | Yes, from the Versions tab (Versions and migration) | Not found | Yes: Process Upgrade, one source version at a time (process upgrade) |
| Canceling a running step, or moving it to another step | Partly: a waiting step is canceled, or moved to a step inside the same parallel sections, and a waiting handler is fired by hand. Any other step cannot be started on its own, and a step cannot be moved into or out of a parallel section (Canceling or moving a step) | Not found: a run is canceled, or resubmitted from its start (cancel or resubmit) | Partly: a designer cancels, pauses or resumes an active node in Monitor mode; moving one was not found (monitoring) |
Architecture¶
| Feature | Orchestra | Power Automate | Appian |
|---|---|---|---|
| Where it runs | Inside a Drupal site, on your own servers or your host's | In Microsoft's cloud; reaching systems on your own network takes the on-premises data gateway, a premium feature (licensing) | On Appian Cloud, or on your own servers (self-managed) (installing Case Management Studio) |
| An API to start and follow work | Yes: an HTTP API with OAuth (The HTTP API) | Not found | Partly: web APIs and a deployment REST API (deployment API); an API for cases was not found |
| License | GPL-2.0-or-later, free | A Premium license per user, or a Process license per flow, for premium connectors and business process flows (licensing) | Commercial |
Where Orchestra differs¶
It runs where your site runs. Orchestra is part of a Drupal site: its data, its users and its workflows stay on the servers you choose, and it costs no license.
Instances wait as long as the work takes. A request that waits months for a document is one instance. In Power Automate, a run ends after 30 days.
Routing on any step, and votes decided early. A join waits for the branches that can still arrive, stops at N of M, or decides a vote as soon as it is settled.
Working time, migration and handlers built in. Deadlines count working time from a calendar, running instances move to a newer version from the Versions tab, and handlers wait for the whole instance, interrupting it or not.
Where the others lead¶
- Products, not a module. They come with support contracts, hosting, monitoring and training, sold by the vendor. Orchestra is a module you run yourself.
- Integration catalogs. Power Automate's connectors reach hundreds of services. Orchestra reaches outside through HTTP steps, Drupal Actions and the Tool API, and programs outside Drupal take its jobs over the HTTP API.
- Standard decisions. Appian's decisions follow the DMN hit policies. Orchestra's decision tables have their own format.
- Maturity. They have years of production use and large customer bases. Orchestra is a new project.
Other platforms¶
Their public reference documentation does not support a line-by-line comparison: what can be found is training material, help pages of past releases, or community forums. What it shows:
- Pega, the other Leader of that Magic Quadrant, is built around cases. A case moves through stages, primary and alternate, each running processes and steps (case life cycle). A Split Join runs subprocesses in parallel and goes on once all, any, or some of them are done, and a Split For Each runs one per item of a list (parallel processing). Service-level agreements set a goal and a deadline, escalate by notifying or reassigning, and count business days on a calendar of workdays and holidays (deadlines). It runs in Pega's cloud, in your own cloud or on your own servers (deployment options).
- Bizagi, a smaller low-code suite, documents compensation: undoing completed steps in transactional sub-processes (transactional sub-processes), which Orchestra does not do yet (#3634775). It does not support ad hoc processes directly (ad hoc processes).
- ServiceNow builds workflows in Workflow Studio, with flows, playbooks and decision tables (decision tables). How flows branch, wait and change version is mostly described in its community forums.