Shift Pattern Thoughts

Can anyone help please. I need to devise a shift pattern but have no idea how to even start. I'm hoping someone can point me in the direction of one. The pattern needs to cover 24/7 all year around. Two people on a shift, currently there are 10 staff so we are working a 5 shift system which is outdated to say the least, on this system if anyone goes off ill then other people on shift have to drop onto 12hrs. If anyone knows of one that could provide 2 floating staff this could be a bonus to cover sickness and holidays. The 10 staff must also cover all holidays. A big ask I know but I'm willing to accept any ideas no matter how little!