SELECT MONTHNAME(b.Fecha_ini) AS Mes, sum(b.Hora_parada ) AS Horas,0 as Paro
FROM orden_trabajo as b
INNER JOIn solicitud_mante a on a.Id_soli = b.Id_soli
where a.Tipo_mante = 'Correctivo Inmediato'
GROUP by year(b.Fecha_ini), month(b.Fecha_ini)
UNION
SELECT MONTHNAME(Fproceso) AS Mes, 0 as horas, SUM(case when Paro_mante = 0 then 1 else Paro_mante end) AS Paro,
from proceso
GROUP BY YEAR(Fproceso), MONTH(Fproceso)