The Spirit of Agile Planning

Two of the Agile Manifesto lines say:
“Working software over comprehensive documentation…
Responding to change over following a plan”
At the time Agile Manifesto signatories, people like Alistair Cockburn and Jim Highsmith wrote these lines because they were dealing with very detailed planning demands from management, detailed processes like the Rational Process, planning from the world of construction, and engineering that demanded plenty of documents, analysis and planning before work starts.
Software however, is more forgiving than cement, and steel; so that is why they said: “Working software over comprehensive documentation.” It does not mean absence of documentation or planning.
The Planning Paradox
What the Agile Manifesto does tell you is that too much planning is a waste of effort, and a waste of time.
Why? Well because:
The further into the future we plan, the less accurate we will be, and the more mistakes we will make until plans become completely useless.
So a plan for one day is more accurate than one for the week,
A plan for the week is more accurate than one for the month,
A plan for the month is more accurate than one for the quarter,
A plan for the quarter is more accurate than one for the year,
A plan for a year is more accurate than one for five years, and so forth.
Agile Planning in Scrum, SAFe and Kanban
In the world of Scrum there is of course the next Sprint or iteration plan, usually a two-week period, but most Scrum experts would agree a 3 to 6 iteration horizon is best, never just one Sprint. That means 1.5 to 3 months planning.
In the world of Scaled Agile or SAFe there is the Program Increment planning, since SAFe deals with multiple teams and large efforts the horizon for the Program Increment is usually 3 months, and SAFe usually recommends to look into the future one or two Program Increments ahead, which means a 6 month horizon.
Kanban uses continuous flow, but this does not mean it does do planning, in fact they do, they just move planning above the level of the team when necessary. So for a single team the horizons of Scrum makes sense 1.5 to 3 months ahead, and for larger efforts of multiple teams (a Kanban Program) 3 to 6 months are advisable.
The Spirit of Agile Planning
You may say, but why are those horizons picked, what is the rational that Scrum, SAFe and Kanban are using?
In short the Spirit of Agile Planning is to see the future in a way that the plans are useful, and beneficial, and not a waste of time. Plans become a waste of time when they become useless because reality on the ground has made them inaccurate, and wrong.
So the Spirit of Agile Planning means that your plan must match the needs of your product, your team, and your environment.
In you are building hardware, plans are usually at least a year long, because you need to manufacture. If you are building software or apps, the horizon will depend on the level of competition, and your industry, it usually hovers are around 3 to 6 months.
Remember as we move further from the present, plans become more and more wishes, and not realities. Agile planning should establish good foundations to build, and move forward. Carefully choose the planning horizon that makes sense for your reality and helps you deliver!