Much of prior work in the area of service operations management has assumed service rates to be exogenous to the level of load on the system. Using operational data from patient transport services and cardiothoracic surgery-two vastly different health-care delivery services-we show that the processing speed of service workers is influenced by the system load. We find that workers accelerate the service rate as load increases. In particular, a 10% increase in load reduces length of stay by two days for cardiothoracic surgery patients, whereas a 20% increase in the load for patient transporters reduces the transport time by 30 seconds. Moreover, we show that such acceleration may not be sustainable. Long periods of increased load (overwork) have the effect of decreasing the service rate. In cardiothoracic surgery, an increase in overwork by 1% increases length of stay by six hours. Consistent with prior studies in the medical literature, we also find that overwork is associated with a reduction in quality of care in cardiothoracic surgery-an increase in overwork by 10% is associated with an increase in likelihood of mortality by 2%. We also find that load is associated with an early discharge of patients, which is in turn correlated with a small increase in mortality rate. Abstract Much of prior work in the area of service operations management has assumed service rates to be exogenous to the level of load on the system. Using operational data from patient transport services and cardiothoracic surgery -two vastly di¤erent healthcare delivery services -we show that the processing speed of service workers is in ‡uenced by the system load. We …nd that workers accelerate the service rate as load increases. In particular, a 10% increase in load reduces length of stay by 2 days for cardiothoracic surgery patients, while a 20% increase in the load for patient transporters reduces the transport time by half a minute. Moreover, we show that such acceleration may not be sustainable. Long periods of increased load (overwork) have the e¤ect of decreasing the service rate. In cardiothoracic surgery, an increase in overwork by 1% increases length of stay by 6 hours. Consistent with prior studies in the medical literature, we also …nd that overwork is associated with a reduction in quality of care in cardiothoracic surgery -an increase in overwork by 10% is associated with an increase in likelihood of mortality by 2%. We also …nd that load is associated with an early discharge of patients, which is in turn correlated with a small increase in mortality rate.We are grateful to the cardiac anesthesiologists and executives at the teaching hospital where this study was conducted. We also thank the Management Science review team as well as Stefanos Zenios, Chris Lee, and Marcelo Olivares for their insightful and constructive comments on an earlier version of this paper. The authors can be reached at dkc@emory.edu and terwiesch@wharton.upenn.edu.

This paper explores the rationing of bed capacity in a cardiac intensive care unit (ICU). We find that the length of stay for patients admitted to the ICU is influenced by the occupancy level of the ICU. In particular, a patient is likely to be discharged early when the occupancy in the ICU is high. This in turn leads to an increased likelihood of the patient having to be readmitted to the ICU at a later time. Such "bounce-backs" have implications for the overall ICU effective capacity-an early discharge immediately frees up capacity, but at the risk of a (potentially much higher) capacity requirement when the patient needs to be readmitted. We analyze these capacity implications, shedding light on the question of whether an ICU should apply an aggressive discharge strategy or if it should follow the old quality slogan and "do it right the first time. " By comparing the total capacity usage for patients who were discharged early versus those who were not, we show that an aggressive discharge policy applied to patients with lower clinical severity levels frees up capacity in the ICU. However, we find that an increased number of readmissions of patients with high clinical severity levels occur when the ICU is capacity constrained, thereby effectively reducing peak bed capacity. Christian TerwieschThe Wharton School, University of Pennsylvania terwiesch@wharton.upenn.eduThis paper explores the rationing of bed capacity in a cardiac intensive care unit (ICU). We …nd that the length of stay for patients admitted to the ICU is in ‡uenced by the occupancy level of the ICU. In particular, a patient is likely to be discharged early when the occupancy in the ICU is high. This in turn leads to an increased likelihood of the patient having to be readmitted to the ICU at a later time. Such "bounce-backs" have implications for the overall ICU e¤ective capacity -an early discharge immediately frees up capacity, but at the risk of a (potentially much higher) capacity requirement when the patient needs to be readmitted. We analyze these capacity implications, shedding light on the question if an ICU should apply an aggressive discharge strategy or if it should follow the old quality slogan and "do it right the …rst time." By comparing the total capacity usage for patients who were discharged early versus those who were not, we show that an aggressive discharge policy applied to patients with lower clinical severity levels frees up capacity in the ICU. However, we …nd that an increased number of readmissions of patients with high clinical severity levels occur when the ICU is capacity constrained, thereby e¤ectively reducing peak bed capacity.

Learning from past experience is central to an organization's adaptation and survival. A key dimension of prior experience is whether an outcome was successful or unsuccessful. Although empirical studies have investigated the effects of success and failure in organizational learning, to date, the phenomenon has received little attention at the individual level. Drawing on attribution theory in psychology, we investigate how individuals learn from their own past experiences with both failure and success and from the experiences of others. For our empirical analyses, we use 10 years of data from 71 cardiothoracic surgeons who completed more than 6,500 procedures using a new technology for cardiac surgery. We find that individuals learn more from their own successes than from their own failures, but they learn more from the failures of others than from others' successes. We also find that individuals' prior successes and others' failures can help individuals overcome their inability to learn from their own failures. Together, these findings offer both theoretical and practical insights into how individuals learn directly from their prior experience and indirectly from the experiences of others. AcknowledgmentsWe thank Mike Luca, Ella Miron-Spektor, Lamar Pierce, and Enno Siemsen for valuable comments on earlier drafts of the paper. We are grateful to Jesper Sørensen, the associate editor, and to the referees who provided constructive and developmental assistance throughout the review process. All errors remain our own.-1 - Learning from My Success and From Others' Failure:Evidence from Minimally Invasive Cardiac Surgery AbstractLearning from past experience is central to an organization's adaptation and survival. A key dimension of prior experience is whether an outcome was successful or unsuccessful. While empirical studies have investigated the effects of success and failure in organizational learning, to date the phenomenon has received little attention at the individual level. Drawing on attribution theory in psychology, we investigate how individuals learn from their own past experiences with both failure and success and from the experiences of others. For our empirical analyses, we use ten years of data from 71 cardiothoracic surgeons who completed over 6,500 procedures using a new technology for cardiac surgery. We find that individuals learn more from their own successes than from their own failures but learn more from the failures of others than from others' successes. We also find that individuals' prior successes and others' failures can help individuals overcome their inability to learn from their own failures. Together, these findings offer both theoretical and practical insights into how individuals learn directly from their prior experience and indirectly from the experiences of others.

We use hospital-level discharge data from cardiac patients in California to estimate the effects of focus on operational performance. We examine focus at three distinct levels of the organization-at the firm level, at the operating unit level, and at the process flow level. We find that focus at each of these levels is associated with improved outcomes, namely, faster services at higher levels of quality, as indicated by lower lengths of stay (LOS) and reduced mortality rates. We then analyze the extent to which the superior operational outcome is driven by focused hospitals truly excelling in their operations or by focused hospitals simply "cherry-picking" easy-to-treat patients. To do this, we use an instrumental variables estimation strategy that effectively randomizes the assignment of patients to hospitals. After controlling for selective patient admissions, the previously observed benefits of firm level focus disappear; focused hospitals no longer demonstrate a statistically significant reduction in LOS or mortality rate. However, at more granular measures of focus within the hospital (e.g., operating unit level), we find that more focus leads to a shorter LOS, even after controlling for selective admission effects. We use hospital level discharge data from cardiac patients in California to estimate the effects of focus on operational performance. We examine focus at three distinct levels of the organization -at the firm level, at the operating unit level, and at the process flow level. We find that focus at each of these levels is associated with improved outcomes, namely faster services at higher levels of quality, as indicated by lower lengths of stay (LOS) and reduced mortality rates. We then analyze the extent to which the superior operational outcome is driven by focused hospitals truly excelling in their operations or by focused hospitals simply "cherry-picking" easy-to-treat patients. To do this, we use an instrumental variables estimation strategy that effectively randomizes the assignment of patients to hospitals. After controlling for selective patient admissions, the previously observed benefits of firm-level focus disappear; focused hospitals no longer demonstrate a statistically significant reduction in LOS or mortality rate. However, at more granular measures of focus within the hospital (e.g. operating unit level), we find that more focus leads to a shorter LOS, even after controlling for selective admission effects.

We use hospital-level discharge data from cardiac patients in California to estimate the effects of focus on operational performance. We examine focus at three distinct levels of the organization-at the firm level, at the operating unit level, and at the process flow level. We find that focus at each of these levels is associated with improved outcomes, namely, faster services at higher levels of quality, as indicated by lower lengths of stay (LOS) and reduced mortality rates. We then analyze the extent to which the superior operational outcome is driven by focused hospitals truly excelling in their operations or by focused hospitals simply "cherry-picking" easy-to-treat patients. To do this, we use an instrumental variables estimation strategy that effectively randomizes the assignment of patients to hospitals. After controlling for selective patient admissions, the previously observed benefits of firm level focus disappear; focused hospitals no longer demonstrate a statistically significant reduction in LOS or mortality rate. However, at more granular measures of focus within the hospital (e.g., operating unit level), we find that more focus leads to a shorter LOS, even after controlling for selective admission effects. We use hospital level discharge data from cardiac patients in California to estimate the effects of focus on operational performance. We examine focus at three distinct levels of the organization -at the firm level, at the operating unit level, and at the process flow level. We find that focus at each of these levels is associated with improved outcomes, namely faster services at higher levels of quality, as indicated by lower lengths of stay (LOS) and reduced mortality rates. We then analyze the extent to which the superior operational outcome is driven by focused hospitals truly excelling in their operations or by focused hospitals simply "cherry-picking" easy-to-treat patients. To do this, we use an instrumental variables estimation strategy that effectively randomizes the assignment of patients to hospitals. After controlling for selective patient admissions, the previously observed benefits of firm-level focus disappear; focused hospitals no longer demonstrate a statistically significant reduction in LOS or mortality rate. However, at more granular measures of focus within the hospital (e.g. operating unit level), we find that more focus leads to a shorter LOS, even after controlling for selective admission effects.