Welcome to the World of Throughput Accounting!
Hello there! If you’ve ever felt like your work is piling up because of one slow computer or a colleague who takes forever to sign off on documents, you already understand the core of Throughput Accounting (TA). In this chapter, we are going to look at a modern way of managing costs that focuses on one thing: speed. We’ll learn how to identify what’s slowing a business down and how to make decisions that maximize profit by focusing on the "bottleneck." Don't worry if it sounds technical—we'll break it down step-by-step!
1. What is Throughput Accounting?
Throughput Accounting is a management accounting technique used in modern manufacturing environments. It was developed based on the Theory of Constraints (TOC) by Eliyahu Goldratt. In the "old days," we used to think that to make more money, we just needed to make every worker and machine work 100% of the time. TA tells us that this is actually a bad idea if it creates piles of unsold inventory.
The Golden Rule of TA: In the short term, almost all costs (like labor and rent) are fixed. The only truly variable cost is the Direct Material.
Key Definitions:
Throughput: This is the rate at which the system generates money through sales.
Formula: \( Throughput = Sales\ Revenue - Direct\ Material\ Cost \)
Operating Expenses: These are all the costs the business incurs to turn materials into throughput. This includes labor, rent, electricity, and depreciation. In TA, we treat these as fixed costs for the period.
Investment (Inventory): All the money tied up in things intended to be sold.
Analogy: Think of a funnel. You can pour as much water (raw materials) into the top as you want, but the water only exits the bottom as fast as the narrow "neck" allows. Throughput Accounting is about managing that narrow neck!
Quick Review:
In TA, we ignore labor costs when calculating "Throughput." Why? Because in modern factories, workers are usually paid a fixed salary regardless of how many units they produce in a specific hour.
2. The Five Steps of the Theory of Constraints
To master TA, you need to know how to handle a bottleneck (the resource that limits production). Goldratt suggested five steps to manage this:
1. Identify the bottleneck: Find the machine or process that is the slowest and limits the output of the entire factory.
2. Exploit the bottleneck: Make sure the bottleneck resource is never idling. It shouldn't take lunch breaks at the same time as everyone else; it should be running 24/7 if possible.
3. Subordinate everything else: Ensure the rest of the factory works at the same pace as the bottleneck. There is no point in the fast machines making 1,000 parts if the bottleneck can only process 100. This just creates messy piles of inventory!
4. Elevate the bottleneck: Spend money to increase the capacity of the bottleneck (e.g., buy a second machine or hire more staff for that specific department).
5. Repeat: Once you "fix" one bottleneck, another process will likely become the new slowest part. Go back to Step 1!
Key Takeaway:
The bottleneck dictates the pace of the entire business. If the bottleneck stops, the business stops making money.
3. Throughput Accounting Ratios (The Math!)
This is the part that often appears in exams. There are three main ratios you need to learn. Don't let the formulas scare you; they are very logical!
Ratio 1: Return per Factory Hour
This tells us how much "throughput" (Sales minus Materials) we earn for every hour the bottleneck machine works.
\( Return\ per\ factory\ hour = \frac{Throughput\ per\ unit}{Time\ required\ on\ bottleneck\ resource\ per\ unit} \)
Ratio 2: Cost per Factory Hour
This tells us how much it costs us to run the entire factory for one hour of the bottleneck's time. Remember, "Total Factory Costs" includes everything (labor, overheads) except materials.
\( Cost\ per\ factory\ hour = \frac{Total\ Factory\ Costs}{Total\ time\ available\ on\ bottleneck\ resource} \)
Ratio 3: The TPAR (Throughput Accounting Ratio)
This is the "Big One." It compares what we earn (Return) to what we spend (Cost).
\( TPAR = \frac{Return\ per\ factory\ hour}{Cost\ per\ factory\ hour} \)
How to interpret TPAR:
- TPAR > 1: The product is profitable. The higher the ratio, the better!
- TPAR < 1: The product is making a loss because it’s not earning enough to cover the factory's fixed costs. We should probably stop making it or find a way to improve it.
Did you know? If you have multiple products, you should always prioritize the one with the highest TPAR. This is very similar to "Limiting Factor Analysis" which you might have studied before!
4. How to Improve the TPAR
If your TPAR is low (or below 1), you need to take action. Looking at the formula, there are three main ways to fix it:
1. Increase the Sales Price: This increases the "Return."
2. Reduce Material Costs: This also increases the "Return" per unit.
3. Reduce Total Factory Costs: This lowers the "Cost per hour" (e.g., cut down on rent or utility bills).
4. Improve Efficiency: Reduce the time a product spends on the bottleneck machine. If a product takes less time on the slow machine, we can make more units!
Common Mistake to Avoid:
Students often include labor in the Throughput calculation. STOP! In TA, Throughput is strictly Sales minus Materials. Labor belongs in the Total Factory Costs.
5. Throughput vs. Limiting Factor Analysis
You might be thinking, "This sounds like the limiting factor analysis I learned in Management Accounting (F2/MA)." You are right! They are cousins, but they have different rules:
Limiting Factor Analysis: Used for long-term decisions where labor can be variable. We maximize "Contribution per unit of limiting factor."
Throughput Accounting: Used for short-term decisions in highly automated environments where only materials are variable. We maximize "Return per bottleneck hour."
Section Summary:
- TA focuses on the bottleneck.
- Throughput = Sales - Materials.
- TPAR should be greater than 1.
- Always prioritize the product with the highest TPAR.
- Inventory is bad in TA because it hides problems and ties up cash.
Don't worry if this seems tricky at first! The best way to master Throughput is to practice calculating the TPAR. Once you get the hang of the three-step ratio process, you'll find it's one of the most logical parts of the PM syllabus!