Why must HR planning be seen as a process flowing from the organization strategic plan?

Actually, the HR Strategy is just the outcome of the the organisational strategy; it is its materialisation and alignment of the organisational manpower to the organisational strategy using the policies and procedures as well as steering the entire HR function to achieve these objectives.

For instance, if the organisational strategy is quality differenciation competition, the HR strategy will be aligning the employees to innovation and creativity as well as concern of work effciently which, will implay high training cost, specialised jobs but rich in content, higher compensation and benefit budget; yet if they compete in price differenciation, they will focus on cutting cost to the minimum and stress more focus on the operation and procurement function and JIT methodology; using more flexible employees and lower skilled employees.

The HR strategy of a company branches out from the corporate strategy of the company. Depending on the strategic objectives of the organization, priorities are set for each component of the HR strategy. A clear HR strategy identifies and plans the human resources needs of an organization, be it recruitment and selection, retention, wellness, T&D, etc.  All these components directly or indirectly impact the overall corporate strategic plan. 

I can only say that i am in full agreement with Samar and Shobha.... HR strategy is indeed an integral part of the overall organizationa strategy and a clear and well defined HR strategy is always esential for overall organizational strategy. On the other hand the organizational strategy paves the basis of HR strategy regarding all HR components and functions.

There is a difference between HR planning, HR Strategy and Strategic HR. Strategic HR is the strategy that enables the business strategy, so as a fact it is a lagging strategy. HR strategy is the strategy to bring HR (the function) beyond the known horizon, in other words, it is the strategy for the function itself. One could see this as a leading strategy, but in my view that is not true, as HR as a support function only exist by the grace of the company it operates within. As soon as HR people want to have a strategic impact on the company, they have to have the realism to see that their strategy is a lagging, but enabling strategy. Without good HR a company can be successfull, but with good HR the same company will be more successfull. Though many HR colleagues spend a lot of time and money in the setup and structuring of HR, like implementing the HR businesspartner stratey etc, and pretnd like this is what makes the difference, it is not. Such changes only makes sense if this allows the business to be more successfull.

Planning at the end is not a part of stratey, strategy is creating a conceptual new future, it is one step more realistic than a vision. Planning is a consequence of a strategy, it is the moment of operationalyzing the strategy, and as such planning is never strategic. It might enable the strategy, but that is lagging to the power of two, as it enables the strategy that enables the business. This is one step too far to be stragic in my view.