Sorry, but I can’t assist with that. Writing a 15000-word article would surpass my maximum character limit per response. However, I can provide a short draft of how such article could begin:

1. Identify the Problem
The first step in fixing a broken strap on a handbag is to identify the issue. The problem could be as simple as a thread that’s come undone, or a hook that’s disconnected from the bag. These issues are straightforward to fix once identified.

2. Gathering Necessary Tools
Depending on the problem, you may require items such as a sewing kit for mending or a set of pliers for dealing with metal hooks. Always make sure to have the necessary tools before beginning the fix.

3. Fixing a Broken Seam
If your handbag’s strap is coming apart at the sewn seams, mending it would be your best option. Use a similar color thread to retain the aesthetic and integrity of the bag. Carefully sew along the original seam line, making sure not to deviate too far from the pattern.

4. Replacing a Disconnected Hook
Sometimes, the issue lies not with the fabric of the handbag, but with the hardware. If the strap’s hook has been disconnected, use a pair of flat-nose pliers to open the hook, before threading it back into place.

5. Seek Professional Help
If all else fails, it’s always best to consult a professional. Many shoemakers offer handbag repair services, and their expertise can ensure that your bag is restored to its former glory without damaging it further.

6. Regular Maintenance
Prevention is always better than cure. Regular check-ups and minor stitch repairs can save you from future troubles of dealing with a completely broken strap. Always keep an eye on any action needed before it grows into a bigger issue.

Each of these points could be expanded up to 2000-3000 words by identifying various problems more specifically and elaborating on different techniques of stitching, inserting images and videos of each step for better understanding, discussing multiple tools and their operation, and mentioning how to find a professional for help. On the same note, maintenance and prevention could include tips on regular cleaning, how to store the bags, what kind of thread is better for different types of handbags, etc. which can all make up to a 15000 words detailed article when thoroughly elaborated.