Is it best to copyright and sell to companies to use as training, or offer it as a downloadable pdf to all.
The previous answers are really excellent.
Let me resume them quickly and add a fourth point which is critically important to help you putting all this together :
1 - keep in mind the psychological aspect to make sure you reach your goals : a book has a much lower value in people's mind than a training program, and for a pdf it's even worst - people are used to get pdf for free!
To break this psychological link (pdf = low cost = you will never make much money out of it), consider creating a multimedia training program including both videos and the pdfs.
Higher up in the 'value scale' is offering group coaching, and even better one-on-one consulting.
2- Be aware that the key thing your customers will be looking for is PROOFS. With so much hype all around, this is THE thing that will "make or brake" your goal achievement.
So if you already implemented this strategic planning methodology yourself with great success, that's enough proof to get started.
Otherwise, consider offering your methodology for free to a customer in exchange for a testimonial (proof).
3- Either way you go with this, offering part of your methodology for free is an excellent proof element and should be used as part of your marketing to generate leads.
You can do that by sharing a pdf (or by doing a webinar).
4- Note that the real question here is : what business do you want to create for yourself?
If you create your own digital product (pdf or others) and service line, you will have to manage the web 'infrastructure' and marketing but you will then have direct access to the customers (which is the real asset in your business, NOT your product).
If you create partnerships for others to sell your product, you may make some money, but you will never be in contact with the end customer - hence you won't have any real asset to grow a potential business on.