KPI 
Key performance indicators (KPIs) are financial and non-financial measures or metrics used to help an organization define and evaluate its success, typically in terms of making progress towards its long-term organizational goals. KPIs are critical metrics that measure actual performance against predefined goals and objectives.
When organizations have defined their goals for the financial year, they need a way to monitor progress towards these objectives. KPIs allow an organization to measure progress and performance by making it possible to understand where current performance stands in relation to planned or expected performance. The organization can act to ensure that goals are met based on the insights provided by KPIs.
Structure
A KPI is an aggregation of entities used to monitor a business requirement. KPIs are calculated by aggregating data over dimensions. For complex KPIs, the aggregation is subjected to some other calculations using business logic. The same KPIs can be applied to various business needs by applying the associated dimension as filters.
A KPI is used to indicate the status or the result of processes, therefore, a KPI is not necessarily always a number, it can also be represented by qualitative statements such high, medium, and low.
Example
A supply chain manager is responsible for monitoring and evaluating operational as well as resource relevant aspects of their organization’s transport network. They require clear insights into the transportation network to identify trends around transport efficiency and punctuality. The supply chain manager might use KPIs such as Delayed Transports (the number of transports that did not reach the customer in time) and Average Cycle Time (the average transport duration from start to delivery). By comparing current performance to target performance, the manager is alerted to any performance issues and can take steps towards resolving them in a timely way.