EngD Research Methods Dan Williams October 2014

Life Cycle Assessment (LCA) The Good It can account for everything! Step by step data collection process The Bad If the process is complex, this can be time consuming. The Ugly Scoping (boundaries, assumptions and limitations) Allocation (how the inputs and/or outputs of an LCA study are divided amongst multiple products) ISO series EngD Outputs LCA for Software Services Data collection methods (two phase)

Mathematical Modelling Used to represent data routes, measurements, and variables. Helps understanding of the complex systems (LCA) that are used with software structures, and to enable estimates of energy consumption and GHG emissions to be made. Top Down – Starting with a known result and modelling backwards Bottom Up - Starting with component parts and modelling forwards/upwards EngD Outputs Models to calculate the energy of cloud services for individuals, organisations and nations. Models to calculate the energy of Operating Systems across organisations

Measurement “a number of measurements must be taken to represent a final value, as data is often inexact” Control – controlling the item to be measured and everything that influences it. Primary – measurements taken using a defined methodology and control Secondary – similar measurements taken using a different or unknown methodology and control EngD Outputs Measurements of a smart phone, laptop, tablet and desktop device at high frequency. Device processing to energy consumption correlations.

EngD Research Methods Dan Williams October 2014