Mizuho Financial Group revealed that the cause of the large-scale system failure that occurred in August was that the recovery was delayed because it did not anticipate the extremely rare trouble of double equipment failure. bottom.
Due to a system failure that occurred on the night of August 19, Mizuho Bank and Mizuho Trust & Banking's approximately 520 stores nationwide were unable to make transactions such as transfers and deposits at the counter from the morning of the next day to around noon. I did.
Mizuho revealed the results of an investigation on the detailed cause of this system failure on the 8th.
According to this, first of all, in this failure, one of the two hard disk devices operating at the same time failed at the part that connects the so-called main system and the terminals of each store.
The remaining one started working independently, but about an hour later, this device also broke down.
According to the survey results, Mizuho and the company that developed the system did not anticipate such an extremely rare trouble that the device would break down twice, and it took time to take measures for recovery such as switching to backup. is.
To prevent recurrence, the company says that it will increase the frequency of equipment inspections, carry out preventive replacements, and formulate a recovery plan to minimize the impact on customers.
Mizuho has received a business improvement order from the Financial Services Agency due to a series of system failures since February, and is required to submit a concrete plan for immediate system repairs by the 29th of this month.