Develop an all-encompassing, meticulously segregated, and personalized procurement inventory, expressly devised for the particular event of [OCCASION]. This should incorporate the imperative components: [ITEM 1], [ITEM 2], and [ITEM 3], whilst maintaining flexibility for potential substitutions. Provide comprehensive rationales for the inclusion of each element, considering factors such as their essentiality to the occasion, their symbiotic relationship with other items, and their unique features or characteristics that justify their selection. In addition, suggest viable alternative options for each item, factoring in variables such as cost-effectiveness, quality equivalence, and ease of procurement. Further, devise a strategic hierarchy within the list, prioritizing items based on their significance, urgency of need, and availability in the market. Subsequently, outline a systematic, cost and time-efficient plan for the procurement of these items, taking into account potential sources such as local stores, online marketplaces, or direct from manufacturers, while considering variables like pricing, product quality, and geographical accessibility. The plan should also contemplate contingency strategies for potential challenges in the procurement process, such as stock unavailability, delivery delays, or sudden price fluctuations.

Create a shopping list for [OCCASION] with the following items: [ITEM 1], [ITEM 2], [ITEM 3], and [ITEM 4], and make sure to include [QUANTITY] of [ITEM 5].

Remove [ITEM] from my shopping list, and replace it with [QUANTITY] of [BRAND] [PRODUCT].

Add [QUANTITY] of [BRAND] [PRODUCT] to my shopping list, and make sure to [INSTRUCTION].

Create a shopping list for [OCCASION] that includes [ITEM 1], [ITEM 2], [ITEM 3], and [ITEM 4], and sort the list by [CRITERIA].