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That time a techie accidentally improved an airline's productivity

Mainframe muddle means extra crossword time for today's hero

On Call Welcome back to On Call wherein a Register reader accidentally improved an airline's productivity by the simple virtue of knowing their stuff.

"Eric" (for that is not his name) spent much of his career working on systems in the airline industry. "Since airlines were the first commercial organisations to use large-scale transaction processing systems, many of their features date back to the late 1950s," he said.

"Some of them were surprisingly sophisticated for the period. In the IBM mainframe world, each user terminal could support up to five simultaneous sessions which were designated by the letters A through E."

A user would simply sign into one of the sessions using an identifier and run processes. There were no passwords – it was a more trusting time – and multiple users in a department often used the same identifier. Once in, users could switch between sessions using a keyboard command.

On the day in question, back in the early 1980s, Eric was at the head office of a certain European national airline and happened to be in the teletype room.

A worker was sitting in front of a blank terminal screen, glaring at the empty display.

Eric decided to try to help and asked the user what the problem was.

"Someone else is using all the computer up," came the response.

Odd. What on Earth could be happening that an IBM System/370 would be brought to its knees? Eric asked for a demonstration. The user agreed.

First, a sign-in for A was attempted. "A in use," responded the terminal. Then he tried B, C, D and E, all with the same response.

"With that," said Eric, "she decided that the entire resource of the mighty IBM 370 mainframe was being hogged by five unknown users scattered across the organization."

Unable to proceed, the user simply sat and waited, getting progressively more annoyed at the recalcitrant computer as she waited to do her day's work.

Five users? Really? Of course the problem was nothing of the sort. "The responses simply meant that there were already five sessions running on the terminal in question," explained Eric.

All the user had to do was pick one to make it active. Instead she stewed until the system housekeeping routine automatically signed out of one or more of the sessions. A process that could take hours.

With a few short words of training, Eric dramatically increased the productivity of the teletype room. He likely also lowered the blood pressure of the user in the process.

The only question was for how long had this been going on? "As far as I could tell this is exactly what she had been doing for several years until the day I chanced to be there at the start of her shift," said Eric.

"Sometimes I miss those simpler days."

Could it be that worst call-out is the one a user never makes, preferring instead to stick with a catastrophically bad process caused by one or two words missing from the training manual?

Share the time you could have saved the day much earlier if only the user had picked up the phone with an email to On Call. ®

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