With the development of informatization and networking, the equipment in the aerospace field has developed into a software-intensive system, and software is responsible for completing most of the functions of aviation equipment. Statistics show that, taking the US F-22 fighter jet as an example, more than 80% of the functions realized by software have reached more than 80%, and the scale and importance of software in the aerospace field are increasing day by day.
▲Software features in aerospace field
The above characteristics are actually the difficulties of aerospace software development. In particular, there are many supporting units for large and complex equipment, and most of the software undertaken by each unit is embedded small-scale software. However, embedded software is more difficult to test than general software, and there is an urgent need for a development model that can improve the efficiency of software development in a short period of time.
The agile (Agile) development model has become the choice of many users. Agile development takes the evolution of user needs as the core, adopts an iterative and step-by-step approach to software development, and aims to speed up product delivery and ensure product stability to ensure software quality. In agile development, a software project will be divided into multiple sub-projects at the initial stage of construction, and the results of each sub-project must be tested to have the characteristics of visualization, integration and operation.
In other words, it is to divide a large project into multiple small projects that are interrelated but can also operate independently, and complete them separately, and during the process, the software needs to be in a usable state all the time.
Is agile really suitable for aerospace project management?
The traditional model of software development in the aerospace field is the V model shown in the figure below:
▲ V-shaped development process in the aerospace field
Starting from the requirements, the construction of the aircraft system can be divided into the following stages:
- Concept determination
- System Definition and Design
- System Development and Testing
- System deployment and operation
▲Image source: https://www.uniroma1.it/en/pagina-strutturale/home
Certain phases of this onerous process can take months or even years to complete, and requirements can change at any time—subsequent processes have to be updated again. At the same time, for safety reasons, all aircraft systems must go through a lengthy certification cycle before they are fully operational, which requires the aerospace equipment team to synchronize design plans and strengthen collaboration within the team.
The Agile development model can solve almost all of the above challenges:
1. Agile development requires that feedback from all stakeholders in the team be quickly obtained, so the aerospace equipment team can focus on iteratively assigning tasks according to the plan and bridging the gap between planning and execution.
Aircraft plans are often large and complex, and how to translate them into specific actions is a common problem. The common standard method is to determine the roadmap through a lengthy Gantt chart, but this method that cannot be updated in real time has relatively low clarity and transparency, and cannot ensure that every team is working on the same road.
In agile practice, using appropriate kanban tools can solve this problem. All departments in the team can track progress from beginning to end, and managers can quickly discover efficiency or other problems in the work process and quickly take necessary measures , to respond in a timely manner.
2. An agile development model with the right tools can solve the problems of hardware testing in the aerospace field.
The biggest challenge of embedded software development in the aerospace field is its over-reliance on hardware for development and testing. Different from traditional Internet products or application software on PCs, embedded software is subject to its special characteristics for specific embedded systems, and often needs to be connected to target hardware to complete debugging and testing.
The rapid iteration of traditional embedded software relies on supporting test hardware, and aircraft hardware usually has poor reusability and high cost. Total cost overruns for aerospace projects will rise to 51% in 2020, according to Deloitte research. Not only are there financial pressures, but project schedules can also be severely delayed as a result.
Not only that, the process of setting up the test environment for embedded software is too complicated, and the requirements for building the test environment are high and time-consuming. The test environment for embedded software in the aerospace field occupies a particularly large area.
SkyEye, the Chinese full name of Tianmu all-digital real-time simulation software , is a hardware behavior-level simulation platform based on visual modeling, which enables aerospace teams to quickly build virtual hardware models, solve problems such as high hardware costs and low reusability, and at the same time ensure product quality .
▲Hardware modeling based on visual graphics
SkyEye can provide the integrated avionics system (ICP) with an environment for building multi-machine multi-function target systems. It adopts a distributed deployment method and cross-links various airborne electronic subsystems through a multiplexed data bus to realize information measurement. , Acquisition, transmission, processing, monitoring and display functions, and complete flight control, engine control, navigation, performance management and other tasks.
▲SkyEye large-scale avionics system simulation case
3. The agile development model can more efficiently handle team disputes caused by hardware resource coordination.
When hardware resources are scarce, engineers will not be able to use the hardware test environment at the same time, and managers need to spend more time and energy on scheduling test resources. Combined with the agile development model, SkyEye can be combined with many tools (such as ZenTao, Jenkins, GitHub, Jihu GitLab, etc.) to create a full-link one-stop platform, and managers can allocate resources more conveniently.
▲Aerospace equipment manufacturing pipeline under agile development mode
In general, combined with suitable simulation tools, the agile development model can find a suitable implementation solution in the highly complex aerospace industry, which will effectively shorten the product delivery cycle.
In the actual project development process, localized agile testing methods suitable for specific situations can be formed according to the actual situation of software engineering, and can be effectively and fully applied in engineering practice, which is of great significance for improving the development efficiency of my country's aerospace software .