Create a traceability matrix in a spreadsheet with Google docs.

traceabilitymatrix.js

/**
 * Instructions:
 * WARNING: all the titles you want to collect should have a common and unique style!
 * 1) Go to your first document.
 * 2) Open your second document in a new tab.
 * 3) On the first document go to Tools->Scripts
 * 4) Paste this code on a blank project
 * 5) Properly fill the variables below.
 * 6) Hit Run onOpen() to add a menu voice
 * 7) Hit REQ->'Create traceability matrix' to run it.
 * 
 */
 
var SPREADSHEETNAME = "TraceabilityMatrix";
var UCSFILEURL = "YOUR URL HERE";
var HEADINGTYPE = DocumentApp.ParagraphHeading.HEADING3;
var PACKAGE_PREFIX = "P";
var UCS_PREFIX = "UCS";
 
 
function onOpen() {
  // Add a menu with some items, some separators, and a sub-menu.
  DocumentApp.getUi().createMenu('REQ')
      .addItem('Create traceability matrix', 'traceabilityMatrix')
      .addToUi();
}
 
 
/**
 * Get all the HEADINGTYPE titles and put them on a new spreadsheet
 */
 
 
function traceabilityMatrix() {
  var now = new Date();
  var timestamp = "" + now.getFullYear() + (now.getMonth()+1) + now.getDay() + now.getHours() + now.getMinutes() + now.getSeconds();
  var newDoc = SpreadsheetApp.create(SPREADSHEETNAME + "_" + timestamp);
  var paragraphs = DocumentApp.getActiveDocument().getBody().getParagraphs();
  var body = DocumentApp.getActiveDocument().getBody();
  var packages = new Array();
  packages.push("");
  for (var i=0; i < paragraphs.length; i++){
    if (paragraphs[i].getHeading()==HEADINGTYPE && paragraphs[i].getText().lastIndexOf(PACKAGE_PREFIX, 0)===0){
      packages.push(paragraphs[i].getText());
    }
  }
    newDoc.getSheets()[0].appendRow(packages);
 
    var bodyUCS = DocumentApp.openByUrl(UCSFILEURL).getBody();
    var paragraphsUCS = bodyUCS.getParagraphs();
    var ucses = new Array();
   for (var i=0; i < paragraphsUCS.length; i++){
         if (paragraphsUCS[i].getHeading()==HEADINGTYPE && paragraphsUCS[i].getText().lastIndexOf(UCS_PREFIX, 0)===0){
           ucses.push(paragraphsUCS[i].getText());
           var row = new Array();
           
           for (var k=0; k<packages.length; k++){
             row.push("");
           }
           row[0]=paragraphsUCS[i].getText();
           newDoc.getSheets()[0].appendRow(row);
         }
    }
  }