Back to Volume 2 | Summer 2017

PPI Position Paper: Defining “Production System” from an Operations Science and Project Production Management Perspective

Executive Summary

What is a Production System? Different disciplines, ranging from manufacturing to civil engineering and construction to project management and Lean, refer to the term, but few define it. One can only assume its meaning is generally taken to be self-evident from the constituent words, e.g. the Toyota Production System is frequently described as a set of principles for “making things”. However, for purposes of Project Production Management, as with other scientific fields, a more precise definition is an essential part of a theoretical framework for making predictions about project execution performance and to identify how to control project execution.

Any method of producing something, whether a physical object or a work of knowledge, entails one or more individual tasks or operations. Each task or operation typically require resources such as equipment or people for its execution, and there typically will be limits on how many resources it can draw upon – capacity. There will be a maximum rate or throughput at which the operation can occur. And there will be an average duration or cycle time to execute the operation. The operation may transform one or more inputs into some output. Production Systems are simply the networks formed by sequences of such individual operations, supplied by inventories and stocks, to which the mathematical techniques of queuing, graph theory and other operational science fields can be applied.

The principal advantage of our more precise definition is that it underpins a full theoretical framework drawn from operations science, to assess theoretical limits on achievable work execution, and to design how to achieve those theoretical limits. The precise definition of Production System provided here enables Project Production Management to model and predict limits on project execution for a given Production System, and identify precisely where buffers can be allocated to optimize key parameters of a Production System: system throughput, system cycle time and system WIP. We contrast its implications with usage in other fields, highlighting the advantages in certain cases.

 

 



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