1# DFX<a name="EN-US_TOPIC_0000001162014185"></a> 2 3## Introduction<a name="section1347419114210"></a> 4 5[Design for X](https://en.wikipedia.org/wiki/Design_for_X) \(DFX\) refers to the software design that aims to improve the quality attribute in OpenHarmony. It mainly consists of two parts: design for reliability \(DFR\) and design for testability \(DFT\). 6 7The DFX subsystem provides the following capabilities: 8 9- HiLog: Implements logging. 10 11- Hiview: Functions as the plug-in platform. 12- FaultLoggerd: Implements fault information collection and subscription. 13- HiAppEvent: Implements logging of application events. 14- HiSysEvent: Implements logging of system events. 15 16## Architecture<a name="section342962219551"></a> 17 18**Figure 1** Architecture of the DFX subsystem<a name="fig18347131919423"></a> 19 20 21![](figures/en-us_image_0000001115926312.png) 22 23## Directory Structure<a name="section62815498425"></a> 24 25``` 26base/hiviewdfx # DFX base repository, which stores compilation-related configurations 27├── hiview # Hiview module, which implements the plug-in platform and event handler capabilities 28├── hiview_lite # Hiview_Lite module, which implements the logging task capability for the mini system 29├── hilog # HiLog module, which implements logging for the system 30├── hilog_lite # HiLog_Lite module, which implements logging for the mini and small systems 31├── hievent_lite # HiEvent_Lite module, which implements event logging for the mini system 32├── hiappevent # HiAppEvent module, which implements application event logging framework and APIs 33├── hisysevent # HiSysEvent module, which implements system event logging APIs and services 34├── faultloggerd # FaultLoggerd module, which implements collection of application fault logs 35``` 36 37## Repositories Involved<a name="section767551120815"></a> 38 39**DFX subsystem** 40 41[hiviewdfx\_hiview](https://gitee.com/openharmony/hiviewdfx_hiview/blob/master/README.md) 42 43[hiviewdfx\_hilog](https://gitee.com/openharmony/hiviewdfx_hilog/blob/master/README.md) 44 45[hiviewdfx\_hiappevent](https://gitee.com/openharmony/hiviewdfx_hiappevent/blob/master/README.md) 46 47[hiviewdfx\_hisysevent](https://gitee.com/openharmony/hiviewdfx_hisysevent/blob/master/README.md) 48 49[hiviewdfx\_faultloggerd](https://gitee.com/openharmony/hiviewdfx_faultloggerd/blob/master/README.md) 50 51[hiviewdfx\_hilog\_lite](https://gitee.com/openharmony/hiviewdfx_hilog_lite/blob/master/README.md) 52 53[hiviewdfx\_hievent\_lite](https://gitee.com/openharmony/hiviewdfx_hievent_lite/blob/master/README.md) 54 55[hiviewdfx\_hiview\_lite](https://gitee.com/openharmony/hiviewdfx_hiview_lite/blob/master/README.md) 56 57