Apartment Building Collapse, Stock-Flow Analysis & more ...
A six-story apartment building in Cairo’s Waili neighborhood collapsed, resulting in at least eight fatalities, according to Egypt’s Health Ministry. Three additional people were injured and transported to nearby hospitals for treatment.
Authorities promptly evacuated surrounding residential buildings as a safety measure, following instructions from Cairo Governor Ibrahim Saber. The cause of the collapse remains unclear, and prosecutors have initiated an investigation into the incident. The structure, originally built in the 1960s, gave way for reasons yet to be determined.
Building collapses are a recurring issue in Egypt, where many aging structures suffer from poor construction practices and insufficient upkeep. Over the years, weak enforcement of building codes and regulations, along with widespread unauthorized construction in low-income areas, has left numerous buildings vulnerable to failure.
Though recent efforts have been made to address illegal building and overcrowding—such as establishing new neighborhoods and the expansive New Administrative Capital—unlicensed and poorly maintained properties persist across large parts of Egyptian cities. As Cairo continues to grow, urban planning and infrastructure challenges remain at the forefront of the government’s ongoing development initiatives ... Read more (3-minute read)
Overview
System dynamics (SD) is a methodology commonly used to assess effects over time in various personal, professional, and societal contexts, for example, the impact of increasing greenhouse gases on climate change and the effect of diet on our health. System dynamics analyses involve stocks and flows that need to be kept under control to prevent detrimental effects within a system. Stocks are resources that accumulate and deplete, and flows are the influx and outflux of certain items that lead to the accumulation or depletion of stocks. The author of the article mentioned above suggests that individuals with higher-order analytical thinking skills tend to perform better in stock-flow analyses than those who make decisions using intuitive techniques. Stock-Flow Failure occurs when individuals use intuitive decision-making techniques and apply correlation heuristics, e.g., expecting that the stock level correlates with the magnitude of inflow or outflow and not the relationship between the two rates. A stock will accumulate when the inflow rate exceeds the flow and will deplete in the opposite case e.g. on a highway, the quantity of cars on the high during a given period would be a stock while the number of cars on-ramping or off-ramping onto the high-way per minute could be a flow. Stock-Flow Failure is observed in knowledgeable and educated individuals, including engineers, mathematicians, scientists, and doctors.
Decision Making and Analytical Thinking
The paper focuses on Little’s Law (LL) as a mediator between analytical thinking and stock-flow performance. A model that proposes mediation suggests the independent variable influences the mediator variable which influences the dependent variable (see Figure 1). A mediation analysis can clarify the relationship between the independent and the dependent variable, particularly when these variables do not have an apparent direct connection (MacKinnon, 2008). Little’s Law is a prevalent queuing problem in inventory management contexts, traffic management scenarios in operational contexts such as managing waiting time in supermarkets. Little’s Law states that the average number of items in the queue (L) is equal to the average rate of arrival to the system (λ) multiplied by the average waiting time of the item in the system (W), i.e., L =λ x W.
The Experiment
Two hypotheses were tested via two studies. ? Hypothesis 1: Analytical thinking has a positive effect on stock-flow performance ? Hypothesis 2: Little’s Law understanding mediates the relationship between analytical thinking and stock-flow performance The two studies were set up as follows. Study One involved a question set across four areas: 1. Analytical thinking was assessed using the Cognitive Reflection Test (CRT). The Cognitive Reflection Test involves asking three questions with a definite correct answer but is structured to entice one to select the incorrect answers using intuitive decision-making. 2. An assessment of Little’s Law understanding. A test of Little’s Law understanding involved asking several questions about various queuing problem contexts (queuing problems with different assumptions). In this case, Little’s Law Understanding used problems as outlined by Read more (4-minute read)
Answered by Robert Halligan (PPI Managing Director and Course Presenter)
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Requirements are totally abstract things. A requirement is simply something that somebody requires. The Oxford English Dictionary defines a requirement as an order, a demand, an imperative. In the most common engineering context, a requirement is a required characteristic of something that is to be engineered or otherwise acquired.
If a requirement is written down, it is now a specified requirement.
A specification is a specific record.
In the two most common engineering contexts, we have requirements specifications and design specifications. The first is a specific record of a set of requirements; the second is a specific record of a design. Thus a requirements specification is the artifact that contains the specified requirements as a set, for the item which is the subject of the requirements specification.
In new product design, a requirements specification for the product would normally drive that design. Once design of the product is implemented, verification of the product will be carried out against the requirements specified in the requirements specification.
The activity of design creates requirements on elements of the solution, e.g. on a subsystem. The requirements on a subsystem will normally be extracted from the design and specified as a set for the purpose of communicating the requirements on the subsystem to the designer or supplier of the subsystem. And so it goes on.
DBA-Business Science Institute-School of Management iaelyon-Université Lyon III Jean Moulin; Harvard University KSG ; MIT xPRO-ASE-Management of Complex Systems; CRMA; CDPSE; Stanford University; University of Oxford
1 个月For the specialists of Infrastructures and Territorial Development, Urban and Regional Development, please review soberly these useful references to explore and exploit adequately.
DBA-Business Science Institute-School of Management iaelyon-Université Lyon III Jean Moulin; Harvard University KSG ; MIT xPRO-ASE-Management of Complex Systems; CRMA; CDPSE; Stanford University; University of Oxford
1 个月J’accepte.