Shift Analysis

University of MichiganMedical Center

Survival Flight

Ann LambrixAnne MurphyRobert Rinck

Industrial and Operations Engineering 481December 12, 1989

TABLE OF CONTENTS

BACKGROUND 1

APPROACH AND METHODOLOGY 2

CURRENT SITUATION 3

ALThRNATIVES CONSIDERED 4

FINDINGS AND CONCLUSIONS 5

HYPOTHETICAL CASE ANALYSIS 8

REALITY 9

ACTION PLAN 10

APPENDIX 11

EXECUTIVE SUMMARY

The scope of this project involved two key questions. First, how many

continuous hours per day should the second Survival Flight helicopter be in

service and secondly, how should those hours be distributed to optimize

the number of completed transfers? A data sample from April of 1987 to

September 1989 regarding requests for flights and actual flights was

analyzed to determine the frequency of requests per hour.

The analysis of all possible 12-hour shifts determined that the

current lOam to 10pm shift is indeed optimal, while the optimal shift for

a 16-hour expansion was found to be 9am to lam.

In deciding whether Survival Flight should expand to a 16-hour shift

several factors had to be taken into consideration. As is shown graphically

in the report, if the 16-hour shift was implemented the percentage of

completed transfers would most likely increase 1.4% over the current

12-hour shift. Applying this 1.4% figure to the number of total requests

recorded for 1988-89, the total increase in completed transfers would be

22 flights.

Our analysis of the gross charges per patient brought into the hospital

through the Survival Flight program within the time period analyzed

showed the average charge per patient is $42,760. The additional gross

revenue for the added 22 flights would therefore be approximately

$940,700.

Overall, operational expenses would increase 7% over and above what

a typical annual increase would involve. This 7% increase equates to a

dollar amount of $134,000.

The profitability of the 9am to lam shift can be examined in two

ways. First, the gross charges obviously outweigh the costs to expand as

it would only take approximately three average flights to cover the cost of

expansion. Secondly, however, average cost per flight would increase from

its current figure of $1600 to a much larger figure of $6100 per flight.

The answer to the question of expansion is therefore that the 16-hour

shift is profitable, but it is not more profitable than the current shift.

Therefore, for the time being we recommend staying with the current

12-hour shift although if circumstances occur that are conducive to

expansion, i.e. additional beds available, substantial increases in requests

etc., the optimal 16-hour shift would be that of 9am to lam.

1

BACKGROUND

Survival Flight, the Emergency Services helicopter transportprogram at the University of Michigan, has been highly successful.Implemented in 1983, the program has continually produced highreturns and, even more importantly, has provided a valuable servicethat very few other hospitals in the area can render.

This program operates in the manner shown in the flowcharton page I of the Appendix. As dispatchers receive calls, termedrequests, they fill out the Hospital Request form on their dispatchscreen. Requests for service are then coded appropriately basedupon circumstances and flight conditions at the present time (i.e.weather conditions, helicopter status). The various codes can befound on page II of the Appendix.

During the infancy of the Survival Flight program, only onehelicopter provided the necessary service. Eventually steady growthindicated a need for further expansion. In 1985, Dr. John Birgeconducted a study to evaluate the feasibility of additional helicopteremergency services. Out of that study came the current schedulingconditions. A second helicopter was added on a 12 hour shift basis.In addition to being able to fill more requests during that 12 hourperiod, the second helicopter provided a backup for the other duringbreakdowns or maintenance. After the implementation of the secondhelicopter, completed helicopter transfers steadily increased andcontinued to increase until just recently. Due to an increase incompetition by other helicopter services in Michigan and northernOhio, both requests for service and completed transfers havelevelled.

This project group has been called upon to determine whetheror not Survival Flight’s second helicopter is still operating on anoptimal 12 hour schedule. If it is not, a new optimal 12 hourschedule would be recommended. Also being considered is whetheror not the current 12 hour shift should be expanded in order that agreater amount of requests for service could be addressed.

I

2

APPROACH AND METHODOLOGY

The scope of the project was defined by the need to addresstwo simple questions. First, how many continuous hours per dayshould the second helicopter be in operation? Secondly, how shouldthose hours be distributed to optimize the number of completedtransfers? A data sample from April 1987 to September 1989regarding requests for flights and actual flights was analyzed to helpdetermine the frequency of requests per hour. A sample breakdownof total requests by hour of day would show where the highestconcentration of requests were in a 24-hour period. Various 12 hourshifts were then compared by what percentage of total requests thatoccurred during the shift. Using this comparison, the optimal 12-hour shift time could be determined. Similar comparisons could bemade for 16, 20, and 24 hour shifts if necessary.

A data sample from the same time period concerning thoseflights missed due to a prior flight was also analyzed. This datawould be used to determine which of those requests missed due to aprior flight could have been flown with the expansion of shift hoursfor the second helicopter. Our reasoning for this analysis isimportant when considering the expansion of service hours.Assuming a given number of requests annually, Survival Flight willbe able to actually fly a certain percentage of those. Maintenance,weather, insufficient beds and cancellations attribute to about 20-25% of the non-completed transfers. These factors remainpredictable and would be difficult to rectify To improve thepercentage of completed transfers, flights missed due to a prior flightwould have to be minimized This minimization could occur byexpanding service hours

A possible expansion of service hours would then require someanalysis of cost Total annual operating costs for Survival Flight aswell as gross revenues brought to the hospital by Survival flightwere used to analyze the financial implications of possible expansion

( Note that the profitability of the program would ultimately bemeasured by comparing net charges to cost due to the sometimes

unpredictable nature of hospital bill payment. Gross revenues,however, still give a benchmark by which profitability could beprojected. Gross revenues and costs could then be broken downaccording to the shift being studied. The gross revenue/costimplications of each potential new shift would be compared to thecurrent operating costs/gross revenues in order to suggest theoptimal shift of operation.

CURRENT SITUATION

3

Currently, the Survival Flight operates one helicopter on a 24-hour shift and another on a 12-hour shift between the hours of 10 A.M. and 10 P. M. The 24-hour helicopter is staffed with two nursesand the 12-hour helicopter is staffed with a doctor and a nurse.

Current operating expenses, taking the figure from the 1989-1990 fiscal year proposed budget, is $2,456,028. This includes allinvolved staff, supplies, actual helicopter costs (lease, fuel,maintenance, overhead, etc.), and other miscellaneous costs. Thegross patient charges last year attributed to the Survival Flight were$37,500,268. With 887 patients averaging about 15 days in thehospital, the average charges for each patient equalled $42,760.

The financial success of Survival Flight can largely beattributed to the excellent service and reputation of its program.Equally important is the fact that Survival Flight brings in patientswho are first, in need of special care, and second, generating highrevenue. However, dwelling on financial success is not necessary.Survival Flight may be able to expand its operation hours to betterserve the surrounding area. As was mentioned in the introduction,total completed transfers has shown a levelling. In the past severalyears the percentage of total requests that resulted in completedtransfers has hovered around 75% to 80%. Again, about 23% of thoserequests that are not completed are considered given. Brieflybrowsing these percentages suggests that there is not much room forimprovement. Data may suggest that the current hours of operationare optimal. However, our task is worth while, in that it gives a

4comprehensive review of the current operating procedures and adetailed look at the implications of expansion.

ALTERNATIVES CONSIDERED

Again, the focus of this study was to answer two questions:How many hours to fly? and Which hours to fly? In order todecide on the optimal shift, all the possible 12-hour continuous shiftswere examined. Data concerning the total requests/hour wasevaluated to determine the 12-hour shift with the highestconcentration of requests. (Note that it is assumed that if a helicopteris staffed when the most request come in, it is likely that the mostcompleted transfers will occur.)

Once an optimal 12-hour shift was found, it was the intentionto weigh the feasibility of expanding operating hours. Although anumber of expanded shift hours were considered, discussion withthe client resulted in a concentration on the 16-hour shift.Advantages of a 16 hour shift over other shifts include potentialstaffing contract problems with shift lengths as well as otherundocumented reasons. All 16-hour continuous shifts wereexamined using two techniques. The first analyzed the 16-hour shiftthat had the highest frequency of requested flights (as in 12-houranalysis). The second technique considered those flights missed dueto a prior flight to predict an increase in completed transfers if anexpansion was implemented.

Also, all costs and gross charges are viewed on a per flightbasis (i. e. the average gross charge per patient is used not theaverage gross charge generated per hour of flight). It had beenconsidered to use a per hour format. A per hour format mayproduce figures that would be interesting to see but the per flightformat produced results were more readily useful.

FINDINGS AND CONCLUSIONS

First, the analysis of all possible 12-hour shifts determined thatthe current 10 A. M. to 10 P. M. is indeed optimal. (See Figure 1)

U)

U)

I’0

I

5

UMMC Survival FlightOptimal 12-Hour Shift

64.72%A64.07%

63.74%

62.21%

67

66

65

64

63

62

61

608A-8P 9A-9P bA-lOP hA-liP

Shift

Figure 1 Optimal 12-hour shift

There is seemingly no significant difference in these four shifts.All four vary by about 2.5% However, when you consider that 2.5%of the total requests will bring in about 30 patients, and you multiplythat by the average revenue each patient generates, it may be wiseto consider the current 12-hour shift over the other 12-hour shifts.

6

83-

82

81

78:

770

76

I

Figure 2 Optimal 16-hour shift

Here again, 80.63% of the requests occur from 8:00am to 12:00midnight; a difference of less than 1%. The 9:00am to 1:00am shiftseems insignificantly optimal. Thus, consideration must be given todata about those flights missed due to a prior flight

The optimal9:00am to 1:00am.time period. (see

shift for a sixteen-hour expansion was found to be81.25% of the total requests occur during this

Figure 2)

UMMC Survival FlightOptimal 16-Hour Shift

-

6A-1OP 7A-1IP 8A-12M 9A-1A IOA-2A

Shift

After reviewing missed flight data (see page IV in theAppendix for raw data breakdown), missed flights due to a priorflight were broken down and evaluated according to proposed 16-hour shifts. (See Figure 3)

Percentage Increase inCompleted Transfers

16 Hour Shifts

1.42%.— 14

,jr.4.4

4.)14C)

C0

C.)14vO

04

2.00% -

1.75% -

1.50% -

1.25% -

1.00% -

0.75% -

0.50% -

0.25% -

0.00% -“TJJ z

0.49%

1.31%

6A-1 OP7A-1 1 FBA-1 2M9A-1 Al OA-2A

Shift

Increase in Completed Transfers/16-hour shift

The 16-hour shift that included the most flights missed due toa prior flight was 9:00am to 1:00pm. These two techniques forproposing an optimal 16-hour shift seem to suggest that the 9:00am-1:00 pm shift is the clear winner. Both the highest percentage ofrequests and highest percentage of missed flights due to a priorflight occur during this time period. If an expansion to a 16-hourshift was justifiable, 9:OOam-1:OOam would be optimal.

Figure 3

0.80°A

1.08%

‘S

HYPOTHETICAL CASE ANALYSIS

Should Survival Flight consider a 16-hour shift? If so, whatwould be the financial implications of such a consideration? Bytaking the financial data from fiscal year 1988-1989 and applyingthe 9:OOam-1:OOam shift to what we already know about flightstrends, a hypothetical case analysis would be instrumental inanswering the above questions.

If the optimal 16-hour shift was implemented, one could bereasonably sure that the percentage of completed transfers for agiven year would be 1.4% higher than the percentage of completedtransfers under the current situation (again refer to Figure 3).Applying this 1.4% figure to the number of total requests recordedfor 1988-89, the total number of completed transfers would be 22flights. (see figure 4)

C)4)p4

04)Q4.4

P

Increase Number ofCompleted Transfers

16 Hour Shifts(Based on figures from fiscal year 88-89)

8

2225 -

__

20 -

15-

10-

5-

0-GA-lOP 7A.11P8A-12M 9A-1A 1OA-2A

Shift

Increase in Completed Transfers/16-hour shiftFigure 4

9

What do these additional 22 patients mean from a financialstandpoint? Our analysis of the gross changes per patient broughtinto the hospital through the Survival Flight program, from October1, 1988 through September 30, 1989, showed the average charge perpatient is $42,760. The additional gross revenue generated by those22 patients would be approximately $940,700. (see page V inAppendix for gross revenue details.)

On the cost side, a budget increase would be unavoidable. Anincrease in hours from 36 hours to 40 hours realizes an 11% increase.After reviewing with our client the methods and reasoning for lineitem budget increases, before and after budget implications can beseen on page VI of the Appendix. Overall, operational expenseswould increase about 7% over and above what a typical annualincrease would involve. That 7% increase equates to dollar amountof $134,000.

Weighing the profitability of the 9 OOam- 1 OOam shift can bedone two ways. First, obviously the gross revenues outweigh thecosts to expand. At the current time, the Gross Revenue/Cost ratiostands at about 19:1 and it would only take about 3 flights to coverthe cost of expansion. Secondly, however, the average cost for thoseadditional 22 flights would increase significantly. At the currenttime, average cost per flight sits at about $1,600. Average cost forthose additional flights would balloon to $6,100. Gross Revenue/Costwould drop to about 18:1 (a sarcastic comparison, but truenevertheless) Is it more profitable to expand to a 16-hour shift?The evidence would suggest that it is profitable, but not moreprofitable than the current optimal 12-hour shift.

REALITY

At the present time, expansion to a 16-hour shift may bethwarted by the lack of hospital beds. However, discussions with ourclient have concluded that the problem of a lack of hospital beds willnot be considered a limiting factor in the expansion due to the

• 10upcoming opening of the new Children’s hospital. This will beimportant to the Survival Flight Program since one-third of thecurrent transport population are infants. Future neonatal unitavailability as well as future opening of U Hospital floors will allowthe percentage of flights missed due to filled beds to decrease. Thisin turn would give more justification for an expansion of hours.

Based on our findings and the above conditions, we recommendthe following:

A. The current 10:OOam-10:OOpm shift for the secondhelicopter is the optimal 12-hour shift.

B. Presently, the 10:OOam-10:OOpm is the adequate shift.

Conditional:C If circumstances occur that are conducive to expansion i.e.

additional beds, substantial increase in requests etc. theoptimal 16-hour shift would be 9:OOam-1:OOpm for reasonsjustified previously.

ACTION PLAN

The course of action for our recommendation isstraightforward. To quote a good man “Stay the course... Fight thegood fight... A thousand points of light.” In other words, the presentoperating procedures are sufficient.

If however a 16-hour shift is implemented, the action planchanges somewhat. Staffing requirements for the 16-hour helicopterwould change from the current situation of one twelve-hour staff perday to two 8-hour staffs per day. This would hold for the AFSMEstaff as well as the medical crew. A part-time pilot must also beadded to the staff, in order to fly the extended hours, at an estimatedsalary of $20,000 per year. Other changes would include the need toorder and store a greater amount of fuel for the helicopter inaddition to medical and surgical supplies which will increase by theproportions previously described. Detailed changes would beaddressed when the conditions for expanding were better known.

rt1

rE

CD I.

I -

SURVWAL FLIGHTFLOWCHART

1

I.

ACCESS FLIGHT CODES

FLIGHT CODE FLIGHT CODE NAME

AF ABORTED FLIGHT

CF CANCFJ I Fr) FLIGHT

EF EDUCATION FLIGHT

& SF GROUND TRANSPORT

Ml MISSED DUE TO WEATHER

M2 MISSED DUE TO MAINTENANCE

M3 MISSED DUE TO PRIOR FLIGHT

M4 MISSED DUE TO OTHER REASONS

M5 MISSEDDUETO COST

M6 MISSED DUE TO CREW CONFIG,

M7 MISSED DUE TO NO BEDS

NON TRANSPORT

OP ORGAN PROCUREMENT

RF REFUEL FLIGHT

RO REQUIRED OTHER SERVICES

SR SEARCH AND RESCUE

TF TRANSPORT FLIGHT

II.

UMMC Survival FlightNumber of Requests VS. Time of Day

April 1987 - September 1989

•112

177

212

11 I II 246

12 I II 216

13 I II 19

14 I 223

15 220

16 •201

17 I 186

18 liii I 119419 liii 119920 184

21 •202

22 iii• 174

23 I152

0 136

ilil •110

2J1I 87

3 105.4

4 71.4

5 62.4

6 52

7 69I • i • I • I • I • I • I

0 50 100 150 200 250 300

Number of Requests

UMMC Survival FlightRequests Missed Due to Prior Flight

fl Apr11 1987 - September 1989

16

3

4

3

3

3

3

3

1

4

18 4

19

20

21

22

23

0

7

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

9

9

9

9

6

5

0.

20

Flights Missed Due to a Prior Flight

ojected Increase in Gross Revenue9 AM - lAM Shift

(Using figures from fiscal Year 1988-89)

PATIENT INFO

Total Gross Revenue Generated 37,500,268

Total Patients 877

Average Gross Revenue/Patient 42,760

FLIGHT INFO

Total Number of Requests 1,570

Total Number of Completed Transfers 1191/76%

PROJECTED TOTALS

1.4% Increase in Completed Transfers 22 ifights2013/77.4%

Additional Gross Revenue Generated $940,700

TOTAL GROSS REVENUE $38,440,968

V.

Projected Increase in Operational Expenses9 AM - lAM Shift

(Using figures from fiscal Year 1988-89)

10 % Increases Before After

Nursing MNA 454,784 500,262AFSME Staff 186,568 205,225General & Office Supplies 57,207 62,928Equipment Maintenance 16,711 18,382Transportation 15,801 17,381Telephone & Telegraph 12,243 13,468Food & Overhead 10,480 11,528Other Contracted Services 7,798 8,578Repairs/Maintenance charge 5,270 5,797Postage 5,000 5,500Other Salaiy 3,300 3,630

11% Increases

Medical/Surgical Supplies 85,199 94,571Pharmaceutical 5,350 5,939Bedding/Linen 8,344 9,262

Lease Overhead

Lease Equipment Rent Overhead 874,894

Add (.84 Fit Hr./Fit.) X (22 Fits.) X ($107/Fit. Hr.) 1,980Add .40 Pilot 20,000Total 897,944

Unchanged

Professional and Administrative Staff 14,812Office Regular 18,446Nursing Administration 42,410Contracted Space Rental 8,355Insurance/Prof. Liabffity 9,354Telephone Rental 11,130Consulting Fees and Overhead 103,292

Totals

Annual Budget $1,956,028 $2,090,174

VI.