Stock on order are the quantities of stock in the pipeline or confirmed as ordered with the suppliers.

Stock-out is a situation in which the demand for an item cannot be fulfilled, i.e. the stock balance is nil. This situation has to be avoided at all costs in the supply chain management cycle of medicines and medical supplies, as it creates acute risks for the health of the population and jeopardizes their trust in the health system. 

(SO) In a results framework, the most ambitious result that an intervention can materially affect and for which it is willing to be held accountable.

Stringent Regulatory Authorities (SRAs) are national regulatory authorities that apply standards for quality, safety, and efficacy that WHO considers similar to its own. To qualify as an SRA, a country must either be a member of or observer to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use or have a mutual, legally binding recognition agreement with a member.

Substandard medicines are those that are out of specification i.e. does not meet quality specifications set by relevant standards and are generally a result of negligence, human error, poor storage conditions etc. with public health impact. They are produced by genuine manufacturers.

Supply chain management is the active management of all activities related to bringing a product or a service to an end user through the cumulative effort of multiple organisations. Its aim is to maximise customer value, achieve a sustainable competitive advantage, and develop and run supply chains in the most effective and efficient ways possible.

Systems thinking is the field of management studies which focuses on an understanding of a system by examining the relations and interactions between its different components. It is an indispensable tool not only for connecting the different elements of the supply chain cycle, but also for linking supply chain management with health system strengthening.

The WHO definition of the total health expenditure is the sum of public and private health expenditures as a ratio of total population. It covers the provision of health services (preventive and curative), family planning activities, nutrition activities, and emergency aid designated for health but does not include provision of water and sanitation.

Traditional medicine refers to all knowledge, skills and practices based on the theories, beliefs and experiences indigenous to different cultures, whether they can be explained or not. These might be used to maintain health as well as prevent, diagnose, improve or treat physical and mental illness.

The treatment episode is a standard period of treatment during which a patient is given a specific medicine. Treatment episodes are used as a base for comparison in healthcare statistics, but are also an important feature for forecasting and quantification, the second step of the supply chain management cycle.