Heuristic Test Strategy

We often use the Heuristic Test Strategy Model (HTSM) in the test, as shown in Figure 1. This tool inspires us to analyze the test strategy and emphasizes how to better adapt to the change of context. Moreover, context change is normal in agile development, and invariance does not exist, which poses a greater challenge to agile testing and requires heuristic test strategies.

You can learn Sun Tzu's "The Art of War," an ancient Chinese military masterpiece, to get some inspiration from it to help us implement context-driven heuristic test strategies, such as： "consider the situation" and "To know the enemy and know yourself, and you can fight a hundred battles with no danger of defeat." "He who can modify his tactics in relation to his opponent and thereby succeed in winning, may be called a heaven-born captain." "It is the rule in war, if our forces are ten to the enemy's one, to surround him; if five to one, to attack him; if twice as numerous, to divide our army into two. If equally matched, we can offer battle; if slightly inferior in numbers, we can avoid the enemy; if quite unequal in every way, we can flee from him." In 2012, several colleagues and I wrote the book "Perfect Test." In one chapter, we discussed how to apply Sun Tzu's Thirty-Six Stratagems in the test. We cited sixteen stratagems of them, including: "letting the enemy off in order to catch him" and "plundering a burning house" "coordinating one stratagem with another" "picking up something in passing" "stealing the beams and pillars and replacing them with rotten timbers" "creating something out of nothing" "resurrecting a dead soul by borrowing a corpse" and so on.

Figure 1. Schematic diagram of heuristic test strategy model

The heuristic test strategy is to select appropriate testing technology according to quality standards, project background, and product elements and deliver acceptable quality to users. The heuristic testing strategy carefully considers numerous influencing factors in 3 aspects, such as quality standards, project context, and product elements, as shown in Figure 2 (the 3rd layer is folded up). We should select appropriate testing technology so that the developed testing strategy is more objective and scientific and thus can correctly guide the specific testing work and make the test faster and better.

Figure 2. Complete schematic diagram of HTSM

Each team is in a specific industry (such as automotive electronics, finance, logistics, etc.) to develop a specific product (a product online), which determines the specific quality standard, industry background, and product type faced by this team. We do not need to consider quality standards, project background, and product elements. And some factors are relatively fixed, and only a few factors may be dynamic and special in the current project, which deserves our special attention.

For example, to develop an onboard system (belonging to the automotive electronics industry), the ISO 26262 standard needs to be considered, and the typical V2X network is involved. We should consider not only the security of this network but also the real-time requirements, including the verification of time synchronization. We will introduce network interface testing tools and simulation technology terms of testing technology. With these test technologies, the test does not depend on hardware (automobile), the test execution speed will be faster, and more abnormal scenarios can be covered.

In the project, we also need to know whether the project's progress is particularly tight. At what stage? If the project is still in the trial stage, the project will not be directly launched, and the quality requirements for safety and compatibility will be lower. You can also know whether it is layered in terms of product elements. What APIs are available? Has the API document definition been completed?

The project-specific Heuristic Test Strategy Model (HTSM) can be completed, as shown in Figure 3.

Figure 3. Schematic diagram of customized HTSM

The process of customizing HTSM is not only the process of applying HTSM but also the process of training our systematic and creative thinking and constantly thinking, enlightening and rethinking. We can quickly explore in depth and breadth, timely capture and adjust contextual factors and risks, and generate good ideas. If you do this exercise frequently, your mind will naturally be more Agile, and your operation will be faster. The HTSM customized in the previous version can also be directly borrowed and then adjusted and optimized to achieve the reuse of test assets. Is it faster to formulate test strategies? It is also a perfect and optimized process to form more valuable test assets.