Implementing Spider Workflow in Power Automate

There are many patterns to implement different types of workflow using Power Automate. But one that strikes me a lot in terms of the dynamicity, is the spider workflow. There are not much of reference out there, it was (in my work history) implemented in a project in one of the prestigious client in Singapore, sparked by my technical architect.

It’s called spider because… of course it looks like a spider. This pattern can be repeated in many projects and even one can implement the template for it in Power Automate. This pattern mainly to overcome a problem when the workflow is not well-defined, prone to change, or to provide dynamic ever-changing workflow without re-work of the entire workflow.

Implementing Spider Workflow

The main concept of this workflow is to loop the process back to the controller after the decision of the next path. The first step to work this out, is to define how many distinctive tasks that a process can do. In the sample diagram above, there are 5 paths that goes everywhere with one of them proceed to end the workflow. The other four, goes back to the controller to decide what’s the next path after an outcome is reached. In the real-world, it can spawn more than 5 or less, depending on the requirement.

The second step, you need to run your thought process to link up between an outcome with the next path. To give you an example, if say the initial flow goes to Approval first (Path 1), definitely it will have 2 outcomes whether it’s Approve or Reject. You could make a story where after the first approval, it will go to another level of approval if the outcome is Approve (Path 1). Otherwise if it’s Reject, you then decide to flow it to End the workflow (Path 3). If you get the feel of your own thought process thoroughly, you could end up having the exact same flow like in the diagram below.

Now, how do we take care of the workflow’s most important mechanism such as notifying the requestor or setting the workflow status once it’s completing one stage? These mechanism you actually can put under the controller itself since it’s executed every time it passes with another path decision.

Be very careful when you run your thought process, do avoid any process that potentially goes into an endless loop (because it can happen). The design itself is perfect, this endless loop can happen due to misconfiguration. Wait, there’s configuration?

Spider Workflow Configuration

There is a configuration to accompany this flow. You could actually leverage on anything to store, literally. Back in my old days, all workflow data are stored as a row in a SQL Server database. Nowadays, you can just work out the JSON configuration and let the configuration be parsed by the flow. Let’s take a sample on how you can define the JSON structure for just one single stage.

{
	"Index": 2,
	"Stage": "Approval 1",
	"Status": "Pending Approver 1",
	"Type": "BasicApproval",
	"SendAttachment": true,
	"AssignedTo": "Dynamic",
	"Outcomes": [
		{
			"Outcome": "Approve",
			"Next Index": 3
		},
		{
			"Outcome": "Reject",
			"Next Index": 6
		}
	]
}

As above is just a simple sample, you could define your own JSON that depicts the flow process. To summarize,

• Index – defines the index of this current path.
• Stage – defines the current stage name (or whatever you want to define as the state of the current flow).
• Status – defines the workflow status for the current path.
• Type – defines the path where to go. If you could link this up with the first diagram above, it’s the Path 1.
• SendAttachment – typically the current controller’s configuration to send attachment to the approver. You can also add your own other configuration.
• AssignedTo – is also the current controller’s configuration to take the approver list dynamically from a table or database. The other values can also be “Requestor” where it will assign to the initiator of the flow.
• Outcomes – defines the routing! You can read it simply by say if the outcome is “Approve”, go to the object that the index is 3. Else if it’s “Reject”, go to index 6.

Now, if you run your thought process, you could define a JSON configuration for the entire process just like below.

[
  {
    "Index": 0,
    "Stage": "Resubmission",
    "Status": "Pending Resubmission",
    "Type": "Closure",
    "SendAttachment": true,
    "AssignedTo": "Requestor"
  },
  {
    "Index": 1,
    "Stage": "Review",
    "Status": "Pending Project Admin Review",
    "Type": "CustomApproval",
    "SendAttachment": true,
    "Actions": [
      "Checked",
      "Return"
    ],
    "AssignedTo": "Dynamic",
    "Outcomes": [
      {
        "Outcome": "Checked",
        "Next Index": 2
      },
      {
        "Outcome": "Return",
        "Next Index": 0
      }
    ]
  },
  {
    "Index": 2,
    "Stage": "Approval 1",
    "Status": "Pending Approver 1",
    "Type": "BasicApproval",
    "SendAttachment": true,
    "AssignedTo": "Dynamic",
    "Outcomes": [
      {
        "Outcome": "Approve",
        "Next Index": 3
      },
      {
        "Outcome": "Reject",
        "Next Index": 6
      }
    ]
  },
  {
    "Index": 3,
    "Stage": "Approval 2",
    "Status": "Pending Approver 2",
    "Type": "BasicApproval",
    "SendAttachment": true,
    "AssignedTo": "Dynamic",
    "Outcomes": [
      {
        "Outcome": "Approve",
        "Next Index": 4
      },
      {
        "Outcome": "Reject",
        "Next Index": 6
      }
    ]
  },
  {
    "Index": 4,
    "Stage": "Super Admin",
    "Status": "Pending Super Admin",
    "Type": "CustomApproval",
    "SendAttachment": true,
    "Actions": [
      "Complete Request"
    ],
    "AssignedTo": "Dynamic",
    "Outcomes": [
      {
        "Outcome": "Complete Request",
        "Next Index": 5
      }
    ]
  },
  {
    "Index": 5,
    "Stage": "Closed",
    "Status": "Completed",
    "Type": "Closure"
  },
  {
    "Index": 6,
    "Stage": "Closed",
    "Status": "Rejected",
    "Type": "Closure"
  }
]

Lastly, this blog is just a conceptual idea that you can implement in each project you go on either with Nintex, Power Automate, K2, or any other cloud workflow out there.