PwC uses drones in audit for first time
PwC has taken to the skies and, for the first time ever, has undertaken a stock count audit using a drone, as part of a wider drive to harness emerging technologies to enhance audit quality
4 Jan 2019
PwC used drone technology to capture over 300 images of the coal reserve at one of the UK’s last remaining coal-fired power stations, Aberthaw, in South Wales, owned by German energy company RWE.
The images from the drone were used to create a point cloud ‘digital twin’ of the coal pile to measure its volume. The value of the coal was then calculated to within 99% accuracy based on that volume measurement.
Richard French, audit partner at PwC, said: ‘Coal stock has a material value on RWE’s balance sheet, so we carry out an annual stock observation and evaluation as part of our audit process. The traditional stock count method involves climbing over the coal pile and using a two metre GPS tracking pole to measure the area and elevation from the ground at various points. The data is then used to build a contour of the reserves and estimate its volume.
‘While the traditional method remains reliable and will still be used for RWE’s formal year-end financial statements, the drone trial was conducted to explore ways of challenging the traditional method of stock counting. It was a classic example of new technology challenging the old - and based on our results, the potential is groundbreaking.’
PwC were testing the use of drone technology to see whether it was accurate and efficient and to compare the benefits of drones to the use of traditional methods. The firm found that:
The traditional method of manually traversing the coal pile can take around 4 hours, whereas using a drone it can be done in half an hour - a reduction of 85%;
The drone captured c.900 data points per cubic metre, obtaining impressive overall accuracy levels of 2cm. This is compared to c.1,200 readings taken across the whole site using the traditional method, therefore the drone enhances accuracy by providing a true, continuous representation of the coal pile;
The preparation for the drone flight requires access to only a limited area of the coal pile and therefore poses less of a health and safety risk, particularly when parts of the coal pile are unstable; and
The flight does not interrupt normal operations on the coal pile, e.g. movement of machinery, and therefore is a less disruptive method.
Elaine Whyte, UK drones leader at PwC, said: ‘This trial with RWE is the first time PwC has used drones for audit stock count purposes. It demonstrates the powerful new perspective that we believe drones can offer for businesses across a wide variety of industries. Sectors with large assets in hard to reach areas are the most obvious starting points for expanding this kind of work further - from mining to agriculture and forestry.
‘Our recent economic report showed that drones have the potential to not only improve UK productivity, but also offer significant net cost savings for businesses to the tune of £16bn by 2030. In this case, drones have allowed us to trial a more efficient service which has the potential to save both money and time, while allowing us to deliver greater insight too. There is also a clear health and safety benefit to using drones for this type of work, without someone having to climb over the coal pile.’
Report by Amy Austin