Table of mean cumulative function for Nonparametric Growth Curve

Minitab displays nonparametric growth information in a table that includes the following:

Time: The successive failure (or repair) times.
Mean cumulative function: The cumulative number of failures (or repairs) averaged over systems. If you enter a cost column, then Minitab calculates cumulative repair costs averaged over systems.
Standard error: The standard error of the mean cumulative function.
95% Normal CI: The lower and upper limits of the 95% confidence interval for the mean cumulative function.

With a nonparametric estimation procedure, the value of the mean cumulative function changes only when a failure occurs.

Example output

Type 1

System: ID

Nonparametric Estimates

Table of Mean Cumulative Function

	Mean Cumulative Function
		Standard Error	95% Normal CI
Time		Standard Error	Lower	Upper	System
33	0.07143	0.068830	0.01081	0.47218	179
88	0.14286	0.093522	0.03960	0.51540	132
250	0.21429	0.109664	0.07859	0.58426	128
272	0.28571	0.120736	0.12481	0.65408	137
287	0.35714	0.128060	0.17686	0.72120	181
302	0.42857	0.132260	0.23407	0.78471	119
317	0.50000	0.133631	0.29613	0.84423	182
364	0.57143	0.132260	0.36303	0.89945	112
367	0.64286	0.128060	0.43506	0.94990	167
391	0.71429	0.157421	0.46374	1.10019	112
402	0.78571	0.149098	0.54168	1.13970	175
421	0.85714	0.170747	0.58008	1.26653	137
431	0.92857	0.158574	0.66444	1.29771	155
444	1.00000	0.174964	0.70969	1.40906	119
462	1.07143	0.158574	0.80165	1.43200	101
481	1.14286	0.137661	0.90253	1.44718	145
498	1.21429	0.149098	0.95456	1.54468	182
500	1.28571	0.187044	0.96675	1.70992	119
500	1.35714	0.191853	1.02872	1.79042	128
548	1.42857	0.219328	1.05735	1.93013	112
552	1.50000	0.242226	1.09304	2.05848	137
625	1.57143	0.280566	1.10744	2.22982	137
635	1.64286	0.259653	1.20522	2.23940	169
650	1.71429	0.256120	1.27912	2.29750	169
657	1.78571	0.270649	1.32679	2.40338	182
687	1.86264	0.266655	1.40692	2.46596	179
687	1.93956	0.260862	1.49012	2.52456	181
700	2.03047	0.254826	1.58771	2.59671	175
708	2.13047	0.274527	1.65498	2.74258	169
710	2.24158	0.268755	1.77214	2.83537	145
710	2.35269	0.257586	1.89833	2.91581	155
710	2.46380	0.240267	2.03516	2.98273	167
719	2.63047	0.347216	2.03084	3.40714	137
724	2.83047	0.425594	2.10800	3.80055	112
724	3.03047	0.443994	2.27405	4.03849	128
724	3.23047	0.410559	2.51818	4.14424	132
730	3.73047	0.471307	2.91221	4.77864	101
730	4.23047	0.410559	3.49769	5.11677	119

Type 2

System: ID

Nonparametric Estimates

Table of Mean Cumulative Function

	Mean Cumulative Function
		Standard Error	95% Normal CI
Time		Standard Error	Lower	Upper	System
19	0.06667	0.064406	0.01004	0.44284	228
22	0.13333	0.087771	0.03670	0.48447	212
39	0.20000	0.103280	0.07269	0.55029	192
54	0.26667	0.114180	0.11521	0.61721	214
61	0.33333	0.121716	0.16295	0.68186	219
91	0.40000	0.157762	0.18465	0.86652	192
93	0.46667	0.159629	0.23869	0.91237	243
119	0.53333	0.207989	0.24834	1.14538	192
148	0.60000	0.263312	0.25386	1.41809	192
173	0.66667	0.261052	0.30945	1.43622	190
185	0.73333	0.274334	0.35227	1.52661	228
187	0.80000	0.269979	0.41289	1.55006	235
192	0.86667	0.264435	0.47658	1.57604	205
194	0.93333	0.257624	0.54335	1.60321	216
203	1.00000	0.249444	0.61330	1.63052	183
205	1.06667	0.257624	0.66442	1.71243	243
211	1.13333	0.264435	0.71738	1.79046	183
242	1.20000	0.269979	0.77210	1.86504	190
250	1.26667	0.257624	0.85023	1.88706	204
264	1.33333	0.277555	0.88664	2.00507	243
277	1.40000	0.295146	0.92615	2.11630	183
293	1.46667	0.280740	1.00786	2.13434	184
306	1.53333	0.324779	1.01238	2.32237	192
369	1.60000	0.309839	1.09468	2.33859	206
373	1.66667	0.335548	1.12325	2.47298	183
382	1.73333	0.319258	1.20810	2.48693	200
415	1.80000	0.342540	1.23962	2.61370	243
416	1.87143	0.340512	1.31007	2.67333	235
419	1.94835	0.338097	1.38662	2.73764	219
419	2.02527	0.349310	1.44435	2.83985	228
432	2.11618	0.347441	1.53391	2.91948	216
434	2.21618	0.345034	1.63337	3.00696	204
441	2.32729	0.341839	1.74512	3.10369	214
447	2.45229	0.337430	1.87262	3.21141	212
448	2.59515	0.331033	2.02109	3.33227	205
448	2.73801	0.315398	2.18466	3.43152	206
460	2.93801	0.298009	2.40832	3.58420	200
461	3.18801	0.449834	2.41776	4.20364	192
464	3.52134	0.511478	2.64893	4.68108	190
503	4.02134	0.535360	3.09778	5.22025	184
511	5.02134	0.535360	4.07443	6.18831	183

Interpretation

For the type 1 brake component, the mean cumulative function is 1.00000 at 444 days. That is, by 444 days, the average number of repairs needed for a single system is 1. The engineer can be 95% confident that the average number of repairs by 444 days falls within the interval of 0.70969 and 1.40906.

When all systems with the type 1 brake component have retired at 730 days, an average of 4.23047 repairs have been made on each system. The engineer can be 95% confident that the true average number of repairs for a system before retirement at 730 days falls within the interval 3.49769 and 5.11677.