Identifying Operational Bottlenecks in Your SME

When a business gets busy, the usual reaction is to hire another person or buy a system. Output often barely moves, because one step in the process caps everything else and the new capacity went somewhere else. Finding that step costs nothing but a notebook and two weeks of attention. This article shows how to map the process, measure waiting time and find the constraint, with a worked car workshop example.

What a bottleneck is

The Theory of Constraints was developed by Dr Eliyahu Goldratt and popularised in his 1984 book The Goal. Its central image is a chain: no chain is stronger than its weakest link, every chain has exactly one weakest link, and strengthening the other links does nothing for the chain as a whole. In a business, the constraint is the step whose output governs the output of the whole operation. For a small business the goal is usually finished jobs out of the door and paid for, and the constraint is the one step that caps how many of those there can be in a day.

Two points matter for owners. First, there is usually only one true constraint at a time, so effort anywhere else is wasted until it has been dealt with. Second, the constraint is often a policy or a person, not a machine. “Only the owner approves quotes” is as real a constraint as a single lift in a workshop.

Step 1: map the process on one page

Lean practitioners call this value stream mapping: drawing every step in the flow of material and information needed to take a product from order to delivery, starting with a current-state map of how things work today. You do not need the formal symbols. A row of boxes on a whiteboard will do.

Under each step write three things: who does it, how long the actual work takes, and how long a job typically waits before that step starts. Involve the people who do the work. The owner’s version of the process is usually the version from three years ago.

Step 2: measure waiting, not just working

Work time is easy to see. Waiting is invisible, and it is where most of the lead time hides. Two cheap measurements over two weeks are enough.

Timestamps on the job card. Add a line for each step with “time in” and “time out”, filled in by staff as they go. After two weeks, average the gaps.

Work-in-progress snapshots. Twice a day, count how many jobs sit at each step, whether being worked on or waiting. The step with the biggest pile in front of it is your first suspect.

Little’s Law, a basic rule from queueing theory, ties the two together: inventory equals throughput multiplied by lead time. Rearranged, average lead time equals the number of jobs in progress divided by the number completed per day. If 18 jobs are in progress and you finish six a day, the average job takes three days, however hard everyone works.

Step 3: find the constraint

The constraint shows a few consistent signs:

• Jobs queue in front of it, while the steps after it are often idle or waiting.
• It is never caught up, even on quiet days.
• Everyone asks the same question: “Has it been through so-and-so yet?”
• When it stops for an hour, the whole day’s output drops.

If the signs point at a person, treat it as a design problem rather than a performance problem. The process has routed too much through one pair of hands.

Worked example: a car workshop in Klang

Consider a workshop with four mechanics, two lifts and an owner who used to be the best mechanic in the shop. After two weeks of job-card timestamps, the map looks like this. The figures are illustrative.

Total work time is under five hours. Total waiting is more than twelve. The snapshots show 18 cars in the workshop on an average day against six completed, so Little’s Law gives a three-day average stay, which matches what customers complain about.

The constraint is not the lifts. It is the owner’s attention, which sits in two steps: approving quotes and quality checks. Both are policy constraints.

Fixes that need no software

1. Exploit the constraint. The owner’s time goes only to work that truly needs it. A written price list for the twenty most common jobs lets the service advisor quote by WhatsApp with a photo of the fault, and at intake customers pre-approve repairs up to RM300 on the job card.
2. Subordinate everything else. Parts runs are batched at 10am and 3pm from a running list, instead of a mechanic leaving whenever a part is missing. Mechanics do not start a car until parts are confirmed.
3. Delegate with a checklist. The senior mechanic does the quality check against a one-page checklist. The owner spot-checks one car in five.

Suppose waiting at approval falls from five hours to one, and waiting at quality check from 90 minutes to 20. Cars in progress drop to about 12 while throughput stays at six a day, so the average stay falls to two days. Only then, if demand holds, does the constraint move to the lifts, and that is the moment to price a third lift or a fifth mechanic. Buying the lift first would have added capacity to a step that was already waiting.

Work through the five steps, then repeat

The Theory of Constraints gives a sequence worth pinning up, known as the five focusing steps: identify the constraint, exploit it, subordinate everything else to it, elevate it if it is still limiting, and then go back to the start, because the constraint has moved and inertia must not become the new one. Most SMEs only ever need the first three steps, repeated every few months.

Checklist before you spend money

• Have you mapped the current process with the people who do it?
• Do you have two weeks of wait times and work-in-progress counts?
• Can you name the single step where jobs pile up?
• Is that step a machine, a person or a rule?
• Have you tried exploiting and subordinating before hiring or buying?
• Do you know which step will become the constraint next?

Key takeaways

• Map the current process with the people who do the work, and record work time and waiting time under each step.
• Collect two weeks of job-card timestamps and twice-daily work-in-progress counts before changing anything.
• Check the picture with Little’s Law: 18 jobs in progress at six finished a day means a three-day average stay.
• Look for a rule or a person before blaming a machine. In the workshop example the constraint was the owner’s approvals, not the lifts.
• Exploit and subordinate first, and price a new lift or a new hire only once the constraint has moved.

How Gusto Style can help

For established SMEs that want this discipline across the whole business, our Platinum Scale Advisory is a fixed-price, three-month programme of twelve sessions covering a strategy review, a business process and quality management review, SOPs for three core processes and a management dashboard for sales, cash flow and operations. Finding and fixing the constraint is usually where the process review begins.