The phrase "a slightly different plan" is correct and usable in written English.
You can use it when referring to a plan that has minor modifications or variations compared to another plan.
Example: "After reviewing the initial proposal, we decided to implement a slightly different plan that better addresses our goals."
Alternatives: "a somewhat altered plan" or "a marginally changed plan."
Rival Planetary Resources has a slightly different plan, in which telescopes would be used to analyse asteroids before craft were sent to mine them.
"Eight years ago, I admit I had a very different plan, a slightly different plan anyway, to leave the Senate," he said.
(That study actually looked at a slightly different plan, which would have raised the minimum wage to $15.25 by 2019).
You might save $1800 on the cost of a slightly different plan, but one trip in an ambulance, or even a few expensive medicines to take care of an eye problem or healing a broken bone could evaporate that discount and leave you $11,000 or more on the hook under deductibles and the out of pocket "cap".
The revisions passed by the United States Senate (the House is considering them) and the Olympic committee's slightly different plan, which was passed here, reduced the number drastically.
If you plan to sit for both the SAT and SAT Subject Tests, you should know that the latter requires a slightly different prep plan.
The Senate and the House proposed slightly different plans for the increases, and a conference committee will seek to reach a compromise.
Each major party is intending to fund its priorities with slightly different plans to rein in tax concessions (superannuation, negative gearing, personal tax deductions) and, in Labor's case, tobacco excise and multinational tax avoidance.
"She has a slightly different approach, but both plans should be explored.
The BrainTrust, though, suggested a plan of a slightly different nature.
The next step, the surgeon reported, will be a new treatment plan using perhaps a "slightly different chemical cocktail" to be devised by Dr. B. J. Kennedy of the University of Minnesota and Dr. Vincent DeVita, Clinical director at the cancer institute here.
