b$)$ Please fill out the S&OP using a level strategy. The overtime constraint is $40$ h per staff per month. A onetime adjustment of workforce at the beginning of the planning period is possible.

$\backslash$table$[[$LEVEL STRATEGY,Period,$],[$Input$,$Unit,$1,2,3,4,5,6,],[$Workforce$,$#staff,,,,,,,$],[$Workforce$,$#$h,,,,,,,],[$Demand$,$#h$,1,020,1,140,1,280,980,896,850,],[$Gap $(=$ Workforce $-$ Demand$),],[$Undertime $(-),$#h$,,,,,,,],[$Overtime $(+),$#h$,,,,,,,],[$Vacation $(-),$#h$,,,,,,,],[$Subcontracting $($t$),$#h$,,,,,,,],[$Derived$,,1,2,3,4,5,6,],[$Regular time,#h$,,,,,,$E$,],[$Hires$,$#staff,,,,,,,$],[$Layoffs$,$#staff,,,,,,,$],[$Calculated cost$,$Unit cost,$1,2,3,4,5,6,],[$Regular time cost,$16[\frac{\text{\$}}{h}],,,,,,,],[$Undertime cost$,16[\frac{\text{\$}}{h}],,,,,,,],[$Overtime cost$,22[\frac{\text{\$}}{h}],,,,,,,],[$Vacation cost$,0,[\frac{\text{\$}}{h}],,,,,,,],[\backslash$table$[[$Subcontracting$],[$cost$]],32[\frac{\text{\$}}{h}],,,,,,,],[$Hiring cost$,$ staff$],,,,,,,],[$Layoff cost$,$ staff$],,,,,,,$Total$],[$Cost per period $$,,,,,,,,]]$