Hey Sharon,
Might try this:
IF(
FIND("ongoing", {Project Status}) > 0,
"ongoing",
IF(
FIND("planned", {Project Status}) > 0,
"planned",
IF(
AND(
FIND("hold", {Project Status}) > 0,
NOT(FIND("ongoing", {Project Status})),
NOT(FIND("planned", {Project Status}))
),
"hold",
"concluded"
)
)
)