# Integrating Sustainable Performance into the Digital Maturity Models for SMEs in Manufacturing
## 3 Literature Review
### Sustainable Performance Measurement
#### 3.3.3 Environmental Performance
According to some authors, the level of environmental impact can also be measured by a company's **ecological awareness**. To quantify this concept more concretely, authors recommend measuring the behaviour of SMMEs in daily operations that may have an impact. Refs. [36; 44; 59] view **reductions in logistics processes**, such as reduced overseas transportation, as a measure of ecological awareness regarding environmental impact. Ref. [34], in turn, considers that reducing the **number of environmental accidents** is an essential indicator for measuring ecological awareness. Finally, product and equipment **durability** also play a major role in environmental performance. This section examines indicators related to the longevity of products and machinery. Developing sustainable products is a key aspect of sustainable development, as noted by [67]. According to [57], **product durability** is a central factor in industrial sustainability. To measure **product durability**, they, along with five other authors, use **product lifespan**. To evaluate it, these authors, along with five other researchers, recommend measuring **product lifespan**. Refs. [65; 67] add that the circular economy strengthens **product durability**, suggesting a second indicator: the **level of product reuse**. A small group of researchers suggests measuring indicators related to smart product design. Refs. [48; 69] use the **percentage of eco-design** in product launch to measure improvements in a company's environmental management. Regarding machinery, refs. [34; 36] suggest assessing the **percentage of retrofitting** as indicators to measure **machinery durability**, while refs. [33; 55] recommend measuring the **repair rate of broken items** to estimate the level of predictive maintenance. In this section, all indicators found in the literature for measuring environmental performance are presented. Some authors mention indicators measuring direct impact, such as the carbon footprint, while others mention indicators for assessing durability within companies. This literature review highlights relevant indicators for measuring environmental performance in an SMME. In summary, the literature review reveals all prevailing thoughts regarding performance indicators in the context of SMME DT. These indicators fall into three categories. Economically, indicators such as **classic financial indicators, continuous improvement** indicators, and **competitive advantage** indicators form the foundation for evaluating a company's benefits. These indicators are crucial for assessing operational efficiency and financial health--key elements for company longevity. Classic financial indicators provide a clear view of the company's financial health. By measuring economic performance, an SMME can more easily make informed investment decisions. Continuous improvement allows an SMME to track the efficiency and effectiveness of its operational processes. By identifying areas needing improvement, the company can optimise operations, reduce costs, and enhance product or service quality. Measuring competitive advantage helps an SMME to position itself strategically in the market. This may include aspects such as technology, innovation, customer service quality, or speed to market. Increasingly prominent in studies, the social dimension is divided into three indicator categories: **health and safety, firm's appreciation**, and societal **impact of the company**. These indicators cover varied aspects, from employee well-being to satisfaction levels to the company's impact on the community. They reflect a growing awareness of the importance of human capital and corporate social responsibility. Measuring health and safety is essential for ensuring a safe and healthy work environment. This reduces accident risks, enhances employee satisfaction, and may also lower costs related to absenteeism and insurance. Measuring worker appreciation helps determine whether staff are satisfied and engaged, which often also affects productivity and worker retention.