A better approach to Scripting Workflows

[former_member190023]

Workflows tend to be part of the core business in SAP Sourcing and business requirements will most often transform a 'simple' workflow process into a very complex one.

Since the introduction of WF in Sourcing (and the TWE 'era') a specific pattern to script workflows has emerged and it has been carried forward into all projects. Today we are going to change that.

**WARNINGS**

• Implementing recommendations in this blog post might make your life easier
• Throughout this blog post it will be assumed that consultants have following knowledge
  • Workflows definition / update / scripting
  • Java EE/BeanShell

WORKFLOW TYPOLOGY

The typology used throughout projects is fairly similar:

• Workflow definition with X number of Approval Steps (total maximum possible steps)
• Approval Matrix Definition maintained *somewhere*
• Specific Approval Sequence picked up in PRE-PHASE-CHANGE script and added to the document into an Extension Collection
• Workflow scripting handles the 'next approver' from the document Extension Collection

So, WHAT IS THE PROBLEM?

For each approval step the script is required to

• Check if approval status is APPROVED or REJECTED
  • APPROVED
    • Approval Sequence is complete -> move document to 'Approved' phase
    • If not complete, add next approver
  • REJECTED
    • move document to 'Draft' (or previous phase)

Pattern in case of APPROVED for above is:

• for WF STEP 1:

if(approvalMatrix.size() == 1) {

  //move to Approved

}

if(approvalMatrix.size() >= 1) {

  //add next approver

}

• for WF STEP 2:

if(approvalMatrix.size() == 2) {

  //move to Approved

}

if(approvalMatrix.size() >= 2) {

  //add next approver

}

• etc ... for all steps

WHY IS THAT A PROBLEM? And why is it complicating our lives?

The pattern above implies that:

• there is one distinct version of PRESCRIPT for EACH workflow step
• similarly, there will be one distinct version of POSTSCRIPT for EACH workflow step

To maintain such a workflow, an IT consultant will have to:

• save/maintain each prescript/postscript version individually
• do a lot of repetitive work for any minor update
• be VERY careful when doing updates not to disturb the process

WHAT IS THE SOLUTION?

The solution is to make scripting GENERIC.

• Single version of PRESCRIPT for ALL steps
  • the script should be able to 'know' from which step it was executed
• Single version of POSTSCRIPT for ALL steps
  • the script should be able to 'know' from which step it was executed

HOW?

• Step 1: Make sure you have a gate identifier. Solution is to 'decode' the current step from the Activity ID (last digit/digits)

• Step 2: Use following code to identify gate -> 'current approval step'
  • Script will get ending digit(s) from identifier:
    • 'approval_gate_1' = 1
    • 'approval_gate_12' = 12
    • 'approval_gate_1485' = 1485 :grin:

import java.util.regex.Matcher;

import java.util.regex.Pattern;

private Integer gate = null;

// btoma - Get the step No. from gate NativeID - last digit(s)

// btoma - to facilitate PRESCRIPT on all steps

void getGate() {

  Pattern p = Pattern.compile("\\d+");

  Matcher m = p.matcher(nativeName);

  while(m.find()) {

  gate = Integer.valueOf(m.group());

  }

}

getGate();

• Step 3: Update WF script code, to use gate instead of hardcoded numbers

if(approvalMatrix.size() == gate) {

  //move to Approved

}

if(approvalMatrix.size() >= gate) {

  //add next approver

}

• Step 4: Copy-Paste your PRESCRIPT on rest of WF steps

• Step 5: Repeat 1-4 for POSTSCRIPT

OTHER RECOMMENDATIONS?

• Maintain scripts locally, in a source control sistem (SVN, GIT).
• Perform changes locally, and copy-paste your script to all WF steps in one go.
• Don't forget about logging and error reporting

The end.

Bogdan Toma