5 Simple Subprocesses Everyone Should Have in Their BPMN Toolkit

An analogy for subprocesses: nested components (like matryoshka dolls) fitting within a larger process, illustrating modular design. As business process maps grow complex, one common pitfall is to create huge, monolithic workflows with no reusable components ajbapps.com. The result is often a tangle that’s hard to maintain or scale. The solution is subprocesses – self-contained mini-processes that can be invoked as needed. In fact, BPM experts emphasize modular design and proper use of subprocesses to keep workflows clear and maintainable ajbapps.com. Subprocesses enhance efficiency by reusing common steps, bolster compliance by standardizing critical workflows, and improve integration by cleanly encapsulating external system calls. Below we outline five simple subprocesses that belong in every BPMN practitioner’s toolkit (especially for ProcessMaker 4 users looking to build scalable, world-class automations).

1. Approval Workflow Subprocess

Approvals are the backbone of compliance in many processes. An Approval Workflow subprocess handles any multi-step review and sign-off routine – for example, routing a request to a manager for approval, handling rework if rejected, and finalizing the decision. Instead of modeling a similar approval flow in every process, you can create one modular approval subprocess and reuse it whenever a sign-off is needed signavio.com.

• What it does: This subprocess encapsulates the steps required to get a decision or authorization. It might include tasks like “Review Document” and “Approve or Reject” with any necessary loops for revisions. All the logic (assigning to approvers, capturing their decision, handling rejects) lives inside the subprocess, which appears as a single task in the main process.

• When to use it: Use an approval subprocess whenever a process requires managerial or compliance sign-off – for instance, expense approvals, content publishing approvals, or any gating decision. If multiple processes share a similar approval pattern, a reusable subprocess is ideal. Workflows often include a standard approval pattern, and modeling it once as a standalone subprocess saves you from re-drawing it every time a sign-off is needed signavio.com.

• Why modular and reusable: By keeping approval logic in one place, you ensure consistency and save maintenance effort. If the approval policy changes (say additional approvers or different rules), you update the subprocess once and every parent process using it inherits the change signavio.com. This modularity not only simplifies your top-level diagrams (one collapsed Call Activity represents the whole approval flow) but also guarantees that every department follows the same approved procedure. In short, a reusable approval subprocess promotes standardization and compliance across all your workflows signavio.com.

2. Notification and Alert Subprocess

Timely communication is key to efficient processes. A Notification subprocess handles sending out messages, alerts, or confirmations in a uniform way. Rather than sprinkling email tasks or API calls throughout your BPMN diagram, you invoke a notification subprocess to handle all messaging needs. This could cover sending an email, an SMS, or a chat alert to the right stakeholders at the right time.

• What it does: This subprocess might accept inputs like recipient, message content, and message type, then perform the steps to dispatch the notification (for example, calling an email service or posting a message to Slack). It can also log the outcome (sent status) or even retry on failure. All these actions are bundled into one callable unit.

• When to use it: Use a notification subprocess whenever your process needs to inform someone or trigger an alert. Common cases include sending a confirmation to a user when a request is submitted, notifying an assignee that a task is ready for them, or alerting a team about a status change. If such notifications occur in multiple processes or at multiple points in one process, a reusable subprocess ensures you don’t duplicate the same email-sending logic everywhere.

• Why modular and reusable: Centralizing notifications in a subprocess improves efficiency and consistency. You can update the messaging format, channel integration, or compliance wording in one place and it applies everywhere that subprocess is used. For example, if your company changes its email template or adds a new communication channel, you modify the notification subprocess once instead of editing many process models. Modular alerts also help with compliance – ensuring every automated email contains required legal disclaimers or every deadline reminder follows the same escalation timing. In fact, event-triggered subprocesses are a best practice for alerts: if a task’s SLA is exceeded, a Timer Event Subprocess can fire off a notification or escalation automatically heflo.com. Using a callable notification subprocess for these event triggers means your escalation messages are handled uniformly every time.

3. Error Handling and Escalation Subprocess

No matter how well-designed a process is, things can go wrong – a system might error out, a data issue might occur, or a step might time out. An Error Handling subprocess provides a reusable blueprint for what to do when an exception or delay occurs. This boosts reliability and keeps the main process flow free of clutter from error paths. Equally important, it enforces compliance by making sure exceptions aren’t silently ignored but are handled in a controlled, auditable way.

• What it does: This subprocess kicks in when a problem arises. It could be triggered by an error event (in BPMN, an Error Event Subprocess inside a process can catch an error thrown in that scope) or invoked as a separate call when a step fails. The error subprocess might log the error details, notify support or responsible persons, perform cleanup actions, and possibly escalate the issue if it’s severe or time-sensitive. For example, if an external API call fails or a task exceeds its deadline, the error subprocess could record the incident and send an alert to a supervisor.

• When to use it: Use an error handling subprocess for processes where you need a defined response to exceptions or timeouts. This includes integrations (e.g., what if a web service is down), approval processes (e.g., what if an approver doesn’t respond in X days), or any critical workflow where errors must trigger follow-ups. Essentially, any time you find yourself modeling a “what if something goes wrong?” path, consider moving that into a reusable subprocess. Many BPMN platforms support event subprocesses that can start on errors or escalations – these can invoke a common error-handling flow.

• Why modular and reusable: Having one error-handling routine promotes consistency and reduces risk. Instead of each process handling errors in ad-hoc ways (or worse, not handling them at all), a standardized subprocess ensures that every exception is managed and logged in a uniform way. This is crucial for compliance and auditing – you can demonstrate that for any failure, the system reacts predictably and records what happened. It’s also far easier to maintain. If you want to change how the company handles certain exceptions (say, send notifications to a different team or implement a retry mechanism), you update the one subprocess and all relevant workflows get the improvement. Modular design also means the main process diagram stays clean and focused on the “happy path,” while the subprocess takes care of the edge cases. As an example, you might implement a non-interrupting event subprocess that invokes a shared “Escalation Process” when a deadline is missed or an error is caught – that sub-process could handle the notification and escalation logic uniformly heflo.com. In summary, a reusable error and escalation subprocess boosts resilience and governance in your process architecture.

4. Data Validation or Business Rule Subprocess

In complex workflows, there are often repeatable checks or transformations – for instance, verifying that a form’s data is complete and valid, or computing a value based on business rules. A Data Validation subprocess encapsulates these checks so that they can be used anywhere they’re needed. This improves efficiency (write the rule once, use it many times) and accuracy (everyone uses the same logic, which supports compliance with business rules).

• What it does: This subprocess takes in data (such as a form submission or a set of fields) and runs a series of validations or rules. For example, it might confirm a customer ID is valid, ensure required fields are not empty, or enforce a policy like “if amount > $10,000 then require two approvers.” It could also enrich data – for instance, look up additional info based on an ID. The subprocess then returns a result (pass/fail or some computed outcome). In BPMN terms, this might be a small flow with script tasks, decision gateways, and perhaps an error end event if data is invalid.

• When to use it: Use a data validation or business rule subprocess whenever multiple processes share the same rule or check. Typical cases include input validation at the start of different processes (e.g., verifying a request form), compliance checks (e.g., does this transaction meet policy), or calculations (e.g., compute tax or discount). If you find that the same decision logic or formula is implemented in various models, that’s a prime candidate to extract into a single subprocess. Even within one large process, if a certain check appears in multiple places, it can be made into a subprocess for consistency.

• Why modular and reusable: By isolating business rules in their own subprocess, you standardize how those rules are applied. This reduces errors and conflicting logic. Any update to the rule (say a policy change or new validation criteria) can be made in one place and instantly affects all processes that use it. It also allows specialized maintenance – for example, a developer or analyst can update the rule subprocess without needing to touch each process model. As SAP Signavio notes, a programmer can create a reusable “Validate X” subprocess that takes an input and returns a yes/no result, without needing to know the details of the parent processes that will call it signavio.com. This separation of concerns makes your overall architecture more robust. Additionally, having a clear validation subprocess helps with compliance and auditing: you can demonstrate that every time data enters a process, it goes through the same rigorous checks. In ProcessMaker 4 (and other BPMN 2.0 platforms), this is often implemented via a Call Activity that invokes a global subprocess for the rule – meaning any process can plug it in and share the same logic.

5. Integration Connector Subprocess

Most automated workflows need to interact with external systems – whether it’s querying a database, sending data to an ERP, calling a payment API, or writing to a legacy system. An Integration subprocess (often implemented as a reusable connector or API call sequence) is a must-have for cleanly handling these interactions. By encapsulating external system calls in a subprocess, you decouple the integration logic from your core workflow, making your design more flexible and easier to maintain.

• What it does: An integration subprocess serves as a bridge between your BPMN workflow and another system or service. It may perform tasks like constructing an API request, invoking a web service, handling the response, and doing error checking. For instance, consider a “Payment Processing” subprocess that takes an order and credit card info, then calls a payment gateway and returns a success or failure status. Inside that subprocess could be tasks for formatting the data, calling the REST API, waiting for a response, and interpreting the result. From the perspective of the main process, however, all of that is one collapsed step (e.g., “Process Payment”).

• When to use it: Use an integration subprocess whenever a process needs to communicate with an external application or database. This could be for things like: retrieving customer data from a CRM, sending a notification to an HR system, updating a record in a finance system, or any cross-application data exchange. If multiple processes interact with the same system, you definitely want a shared connector subprocess. Even for single-process integrations, it’s wise to isolate the integration so that it can be updated or expanded independently.

• Why modular and reusable: There are several big benefits to a modular integration approach. First, it simplifies the main process – you replace complex technical steps with one high-level activity, making the BPMN diagram easier for non-developers to understand. Second, it ensures consistency: every process calling System X does so in the exact same way via the subprocess, reducing duplicate code and errors. If the API for System X changes, you update the subprocess rather than hunting through multiple diagrams. This greatly lowers maintenance effort. Third, it improves testability and isolation – you can develop and troubleshoot the integration in one place. Notably, this pattern is considered a best practice in workflow design: for example, a payment processing logic can be encapsulated in a separate workflow and invoked using a call activity, specifically to maintain modularity and reusability spiff-arena.readthedocs.io. In ProcessMaker 4, which supports BPMN 2.0 call activities, you can build these as sub-processes (sometimes called connectors or scripts) that any process can invoke. The result is an integration layer that is robust and scalable. By having these connector subprocesses in your toolkit, your automation can easily plug into new systems or be reconfigured, all without disrupting the high-level process flow.

Conclusion and Next Steps

By incorporating these five subprocesses into your BPMN toolkit, you lay the groundwork for more efficient, compliant, and integrated workflows. Each of these subprocess patterns – Approval flows, Notifications, Error Handling, Data Validation, and Integrations – helps break down complexity into manageable, reusable modules. The payoff is a library of building blocks that you can mix and match to orchestrate sophisticated processes without starting from scratch each time heflo.com. Your diagrams stay cleaner and your team knows that behind each collapsed sub-process is a well-tested, standardized implementation.

Designing processes in this modular way is exactly how enterprise-grade workflows are built. It not only makes individual projects easier to understand, but also strengthens governance (since common functions are centrally maintained) and speeds up scaling (since new processes can leverage existing components). As you adopt these subprocesses, remember that the goal is a balance between clarity for stakeholders and technical completeness for developers – and subprocesses let you achieve both by hiding complexity until it’s needed heflo.com.

Ready to build a world-class, scalable process architecture? AJBApps is here to help. As the original architect of ProcessMaker 4, we have unparalleled expertise in designing modular BPMN 2.0 workflows that are efficient and resilient. Whether you’re looking to refactor a monolithic process or expand your automation portfolio, we can guide you in applying these subprocess patterns (and many more) effectively. Contact AJBApps for a consultation and let’s turn your process ideas into an orchestrated reality – with best-practice design and expert insight at every step.