The controversial i6 system was scrapped last year after testing discovered a series of glitches just as it was due to go live.
Martin Leven, Police Scotland's head of IT, said the failure of the system had been a "blow" which meant data had to be inputted into multiple systems, wasting police time.
Appearing before MSPs, the Scottish Police Authority (SPA) said there had been an "overconfidence" the project would be delivered.
The project, which was due to provide savings worth £200m, was abandoned last year when the SPA, Police Scotland and multinational technology firm Accenture mutually agreed to end the contract.
Appearing before Holyrood's justice sub-committee on policing, Mr Leven said the failure of i6 meant police officers continued to input data into multiple system.
He said the project's cancellation had made it more difficult for Police Scotland to roll out smart devices such as tablets to officers.
And he said the continued use of multiple systems meant officers and staff were unable to move to work in other parts of the country without IT support to help them access their computer.
Asked if the effectiveness of officers had been affected by the scrapping of the project, he said: “I believe it has. There’s no detriment to what they were doing before. Officers and staff from right around the country operate in the way they did before i6 was due to come in.
“What I would say is that there’s been a loss of opportunity with i6 not going live and delaying that opportunity until we get a more centralised system.”
Mr Leven said the successful implementation of a new IT system would mean "less time spent at keyboards and more time in the community".
SPA chairman Andrew Flanagan told MSPs there had been an "overconfidence" the project would be delivered successfully.
He said: "The i6 approach was a very risky approach to delivering systems of this scale."