Inefficient (adjective)

1. Not able to perform or produce effectively with the least waste of time and effort.
2. Not able to function or operate in the best or most economical way.
3. Not able to use resources effectively.

Origin:

From in- ("not") + efficient.

Examples:

1. The system was inefficient and needed to be redesigned.
2. The organization was inefficient and needed to be restructured.
3. The engine was inefficient and needed to be replaced.
4. The process was inefficient and needed to be streamlined.
5. The government was criticized for being inefficient.