Lean project management is the comprehensive adaption of other lean concept like lean construction

Lean construction

Lean Construction is a combination of original research and development in design and construction with an adaption of lean manufacturing principles and practices to the end-to-end design and construction process. Unlike manufacturing, construction is a project based-production process...

, lean manufacturing

Lean manufacturing

Lean manufacturing, lean enterprise, or lean production, often simply, "Lean," is a production practice that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination...

 and lean thinking into project management

Project management

Project management is the discipline of planning, organizing, securing, and managing resources to achieve specific goals. A project is a temporary endeavor with a defined beginning and end , undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value...

 context.
Lean project management has many ideas in common with other lean concepts; however the main principle of lean project management is delivering more value

Value (economics)

An economic value is the worth of a good or service as determined by the market.The economic value of a good or service has puzzled economists since the beginning of the discipline. First, economists tried to estimate the value of a good to an individual alone, and extend that definition to goods...

 with less waste

Waste

Waste is unwanted or useless materials. In biology, waste is any of the many unwanted substances or toxins that are expelled from living organisms, metabolic waste; such as urea, sweat or feces. Litter is waste which has been disposed of improperly...

 in project context.
Lean project management has many techniques in order to be applied into projects and one of main method is standardization

Standardization

Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....

. Key techniques are those "inherited" from Agile software development like: blame-free employee involvement, the need for a strong facilitator, pipelining, etc.