Running sensitivity / scenario analysis on a portfolio
1. How often do Asset managers / owners typically run sensitivity / scenario analysis?
2. What variables do you use / assumptions you make? For example, inflation \~2%.
3. What are some tools/software you use or do you use excel? Any limitations? What's something that you would like to see in a software when it comes to sensitivity/scenario analysis?

For context, we are building  portfolio and valuation product for CRE. 
[{"id": "g7vqhqs", "text": "1) approximately 42 times per year.\n\n2) depends on market, asset, what sensitivity I am using. \n\n3) Microsoft Excel", "replies": [{"id": "g7vr49n", "text": "What are some assumptions you make when running the analysis? What data do you collect? Mind walk me through how you do it? Thx.", "replies": [{"id": "g7vrzu3", "text": "All kinds of assumptions, rent growth, expense growth, tax reassessment, exit cap rate, floating rate debt index fluctuations. I personally use data tables in excel (what if scenarios).", "replies": [{"id": "g9ezk84", "text": "Got it. Some questions:\n\n1. How do you determine expense growth? Does it depend on rent growth?\n\n2. Can you share the formula you use for scenario planning? Are you looking at changes in cash flow or some other metric?", "replies": [], "depth": 4}], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "g7vwimn", "text": "(1) about 1,000,000 times a year. No joke, it\u2019s constant - something goes bump, run a scenario. New lease, run a scenario. Lease terms changed? Run a scenario.\n(2) everything from LIBOR to every economic assumption about a lease to the MLAs to cap rate to timing.... anything and everything\n(3) excel does everything. Excel is the golden god. The only limitation is ones ability to operate it. Oh and I guess that data table inputs need to be on the same page as the data table but that\u2019s easy enough to just link stuff thru to a new page.", "replies": [{"id": "g9ez7vn", "text": "Thanks. For context, I am building a CRE scenario planning tool. \n\n1. When you say run a scenario, do you mean cash flow under different scenarios or are you looking for something else?\n\n2. What's your data source for LIBOR, Inflation?\n\n3. What's MLA?", "replies": [{"id": "g9g4b2v", "text": "(1) just a different cash flow\n(2) Chatham financial\n(3) market leasing assumptions", "replies": [], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "g7wh291", "text": "1. Depends. Adhoc scenarios, especially at the asset level is probably daily. Portfolio sensitivity is normally event-driven (refi, audit, raise) or part of quarterly cycle\n2. IMO macroeconomic are typically set and forget unless it's lender collateral examination and risk management. The major exception for this is if they are used in place of a more detailed (and accurate) amount. As example, suppose you feel that HVAC and electrical costs will climb because of greater airflow in an office building within a portfolio. You could raise inflation for OPEX/CAPEX to increase by some amount, which I've seen alot, or increase the specific amounts and timing at the property in your forecast assumptions. The latter is of course more accurate but at a portfolio level more difficult to do dynamically\n3. Excel is great until it isn't - everyone has pride in their own model however changes (especially hard coded #'s) are difficult/impossible to track intelligently. I've seen some analysts track every change and its rationale in a separate word doc. What's needed is a way automate the easy stuff yet allow for the flexibility that an Excel wiz wants. As important, it needs to be able to compare and trend changes between many versions.", "replies": [], "depth": 1}]