EMD Duration . The original research report indicated that for 24 programs completing EMD between the years 1980 and 1993, the average duration of the EMD phase was 7.4 years. The most recent addition to this data shows that for 37 programs (including the original 24), completing EMD between 1980 and 1997, the average duration of the EMD phase was 7.8 years. This summary data can be broken down into year groups as well as planned and actual duration, and the ratio of actual to planned duration. The latter may be a rough estimate of the realism of the original program planning. Table 2 shows this data.

Year EMD Completed	Average EMD Duration
	Planned	Actual	Ratio
1980 - 1988   (n=12)	4.2 yrs	6.5 yrs	1.6
1989 - 1992   (n=11)	4.9 yrs	8.0 yrs	1.7
1993 - 1996   (n=12)	5.8 yrs	8.7 yrs	1.6
1997   (n=1)	5.0 yrs	7.9 yrs	1.6

TABLE 2. Average EMD Duration