A Safety Case, and all of the documentation on which it is built (not least of which is the Hazard Log) is absolutely essential for anything as complex as an aircraft, a train, a signalling system, or anything else that isn't trivial. It has to take into account people, procedures, and equipment. It's not something you should ever look to cut from your budget.
I worked at Boscombe Down as a safety engineer for a few years in the nineties...we made our recommendations, based on solid evidence, and they were often ignored by MoD on the basis of cost or simply because they thought they knew better. I'm still working as a safety engineer (although no longer associated with military aviation) and it's still all too often an uphill task to get the holders of the purse strings to listen. Thankfully, we are now backed up with legislation and international standards (the principles of which are readily applicable to military aviation) so not every day involves a flagellated deceased equine...