Team working on controversial Post Office Horizon EPOSS software was the ‘joke of the building’

The ICL team working on the Post Office Horizon IT system lacked experienced developers and used bad software development practices, a former worker has told the public inquiry into the scandal.

Software developer David McDonnell told the Post Office Horizon IT Inquiry that, at the very minimum, it was clear that the critical cash account component of the software, which enables subpostmasters to balance their accounts, should have been rewritten.

Some subpostmasters were sent to prison for financial crimes based on evidence from the software, and the lives of many more were ruined when they were blamed for accounting errors.

Thousands of subpostmasters began having problems balancing accounts when, in 1999, the Horizon system was rolled out to Post Office branches to replace manual accounting. The following two decades saw subpostmasters blamed for unexplained accounting shortfalls and made to repay them.

A total of 736 subpostmasters were prosecuted for financial crimes based on evidence from the Horizon system, which has since been proved to contain errors that can cause such losses. More than 80 former subpostmasters, some of whom spent time in prison, have so far had wrongful convictions overturned.

McDonnell joined ICL Pathway in 1998 to work on the Post Office Horizon Systems Electronic Point of Sale Service (EPOSS) development team, initially as deputy development manager. Giving evidence at the Post Office Horizon IT Inquiry, he explained that he quickly learnt of the problems being experienced by the ICL team tasked with developing the EPOSS software.

During his interview by ICL, McDonnell was told of “deep concerns” over the quality of the team developing the EPOSS system, and that many of the team could not handle the work they had to do. After joining the team, he saw for himself the sub-standard quality of the team developing the software.

He told the inquiry: “I would say out of the eight in the team, two were very good, another two were mediocre but we could work with them, and then there were probably three or four who just weren’t up to it and weren’t capable of producing professional code.”

McDonnell said when he arrived, the EPOSS development team was “like the Wild West” with “no standards, a lack of rules and no design”.

“It was crazy. I had never seen anything like it before or since,” he said. “I wouldn’t say it was a holiday camp, but it was free format. The EPOSS team was the joke of the building.”

McDonnell told the inquiry how, such was the awareness of problems within the company, tech professionals were even sent from Japan by Fujitsu, which owned ICL, to assess the team and the well-known problems, but “they came, they sat and they went, without talking to anybody”. He said he had been told to give these workers everything they needed, but was never told if anything came of this.

McDonnell was part of a task force set up to investigate problems with the Post Office EPOSS system and a co-author of a report it produced on its development. The task force was set up by Terence Austin, the former systems programme director at ICL Pathway, who was questioned in the public inquiry on 27 October.

The report produced by the task force concluded: “Whoever wrote this code clearly has no understanding of elementary mathematics or the most basic rules of programming.”

McDonnell told the inquiry that concerns over the cash account software were raised with former Fujitsu chief architect Gareth Jenkins, but that he denied the issues and McDonnell was unable to get him to support his call for a software rewrite. “When we started having conversations like that, he became evasive with me. I was never able to get him back on-site again after this.”

Jenkins is one of two former Fujitsu/ICL employees under investigation by the Metropolitan Police for potential perjury when giving expert witness evidence about Horizon during trials of subpostmasters accused of fraud, false accounting and theft.

McDonnell was offered a new job to lead the team as part of a restructure, but when he demanded the cash account software be fixed as a condition of accepting the job, the conversation was brought to a halt. “It was very clear the cash account software was not going to be rewritten,” he said.

Computer Weekly first reported on problems with the Horizon system in 2009, when it made public the stories of a group of subpostmasters (see timeline of articles below).