Basics of Load Testing

11 januari 2021 om 10:00 by ParTech Media - Post a comment

Testing is one of the main elements of application/system development. Testing ensures that your users can do what they want without getting frustrated. Without testing, you risk the presence of bugs and delayed response time causing frustration to your user. When your user is frustrated, it leads to a poor customer experience.

When your customer doesn’t have a great time with your application, good luck seeing him use his application one more time. Remember - your customers will never love a product that doesn’t perform as promised.

It may be harsh, but we live in a fast-moving world where your user’s experience is all that matters. If your user experience is not on point, your customer will move on to your competitor. That is exactly why testing is a lifelong process that you should be doing constantly. Stop testing and you lead your way to failure.

In this blog post, let’s take a look at what is Load testing and how it will help you develop a better application.

Table Of Contents

  1. What is Load testing?

  2. How is Load testing done?

  3. What kind of questions can you answer with a load test?

  4. What are the different kinds of performance tests out there?

  5. Verdict

What is Load Testing?

Load testing is the process of creating a simulation for an application or a system that you are developing. It is mostly down to products that are nearing completion ( software in the final stages of development ). Developers may also test old products when they have launched a new update or made some changes in the software.

How is Load testing done?

Developers use testing software that runs specific tests on your application/system under test. These software programs are designed to simulate the real-life application of the application after it is launched.

For example: Let’s say that you have SaaS software which you are creating for medium-sized organizations. You create this software with a maximum of 50 users simultaneously.

So your load test would mimic the usage patterns of 50 users for your application. After you run the testing software, you can get an idea if it can handle the load that you’ve designed it for.

If the application crashes anywhere before 50 users, you need to rework the application and its structure. Your developer team needs to identify the areas which might be problematic and rework them.

If your application runs smoothly at 50 users, you have matched your theoretical expectations with practical expectations. In simple words, it means that your application/system is ready to be released.

Here’s how a load test works in real-time

What kind of questions will be answered with a Load Test?

As a Developer or a project manager, here are some questions you can answer with a load test.

  • What is the average response time for each user in my application?
  • What is the maximum usage limit of my application?
  • Is the current IT infrastructure sufficient to handle the predicted loads?
  • What is the accuracy of the results generated by my application?
  • How easy it is to maintain synchronization among users?
  • Are there any places of bottlenecks in my application?
  • Was the application stable under the current load metrics?
  • Was the system lagging at any specific point of time?
  • If it was, what was the function that predominantly caused that?
  • If that function is irrelevant, how can we remove that?
  • If that function is relevant to the application how can we make it better?
  • Are there any page load issues with a high load?

And finally the most important question of all - Does my application satisfy the needs of my client or organization?

This is important because at the end of the day your well-designed applications and systems will be used to satisfy the needs of your end customer. To satisfy the needs, it must do what it is designed to do.

Let’s assume that you have a client who wants a notification to pop-up after a user has used the application for more than 5 minutes. This notification must pop-up for every single user. This client expects up to 2000 concurrent users for his application.

Concurrent users are a bunch of people who log in to an application, perform a very specific set of activities at the same time and log off. It is like a WhatsApp group where everyone logs on when a message is posted. After reading the message and maybe replying back to it, most of them will log off.

Now you will set up a load test that mimics the usage patterns of 2000 users logging in at the same time. You will then measure the precision of the ‘Pop - up’ in each test set and measure it accordingly.

What are the different kinds of performance testing models?

Apart from load testing, you have a bunch of live testing models for your applications and systems. Here is a list of some of the commonly used tests.

Baseline Testing

Baseline testing is a way to identify the working of your application in the baseline metrics. Baseline testing helps you figure out the performance of your system on very minimal loads. Once you record the readings on these minimal loads, you can add more stress to identify maximum loads and breaking points. The main goal of this test is that it gives you a reference on how a system performs under normal conditions.

Load testing

Under load testing, you may increase the load from the baseline value and see how the system reacts to it. This is the test where you monitor factors like

  • Response time
  • Server conditions
  • Overall performance

The goal of this test is to identify if you’re theoretical predictions match the practicality of your applications and systems. In summary, it helps you to identify if the system matches your theoretical predictions

Stress testing

Under stress testing, you need to identify the load where your system actually malfunctions or stops functioning. Yes, the goal of this test is to take your system to the point of no return and just break it. The goal of this test is to identify the load at which the system stops functioning. A more precise goal would be to identify the reason for the system breaking at this critical load.

Scalability testing

Developers apply scalability for applications that are in the final stage of completion. It helps you identify how the performance of your application changes with frequent changes in load characteristics.

Let’s say that you have 2000 users and the system has a response time of 2.5 seconds. If 2000 new users log in to the system, the response time must still be at 2.5 seconds.

The performance of your system must also scale with a scaling load.


A load test will help you get past the most common problems with your application before it launches. It also helps you refine the system and make sure it meets the real-life needs of your clients or organizations. Load testing might be tedious, but it’s necessary to develop a successful application/system.