Production standards for yemane (Gmelina arborea Roxb.) lumber manufacturing

The results of the study produced the following results: 1. The work elements in yemane lumber manufacturing have been identified as log loading, log positioning on the carriage, slabbing and lumber sawing which are considered as productive elements. The supplemental elements have also been identified as scaling, and log turning. 2. Some factors that were considered to influence the expected time of conversion of yemane logs into lumber have been analyzed and quantified using the continuous timing method according to work elements which are as follows: average diameter and loading distance for loading operation; average diameter, length, and log defects such as knots, sweep, ovality, and taper for log positioning on the carriage; average log diameter, lengths, and the aforesaid log defects and number of slabs for slabbing; and average diameter, length and number of lumber for lumber sawing activity. 3. Using stepwise regression analysis, the multiple regression equation for each of the main work elements as functions of the respective identified variables were derived and integrated into sawing cycle time (SCT), giving the final equation: SCT=(-2.7731 + 0.1214D + 1.2298 L + 0.2641 Dist. + 0.4077 NS + 0.5335 NL + 0.0982 K) (1 + 0.2985). This means that sawing cycle time is significantly influenced by diameter (D), length (L), loading distance (Dist.), number of slabs (NS), number of lumber (NL), and knots (K). Sawing cycle time (SCT) is further increased by the supplemental element time and delay factor of 0.2985. In terms of work elements loading time is significantly influenced by loading distance from the log site to the carriage and diameter. Slabbing time is significantly influenced by log diameter, length and major knots present in a log. Lumber sawing time is significantly affected by log diameter, length and number of lumber produced per log. No variables showed strong linear relationship with log positioning time, hence, no linear regression equation was derived. The average log loading time was used as standards for calculating the total SCT. On the other hand, volume yield is found to be positively and significantly contributed by log diameter and length but decreased significantly by increasing percent sweep. Subsequently, production standards in board feet per hour and per day bases for lumber manufacturing were derived and presented. 4. Production cost standards were derived based on machine maintenance and operating costs. Production costs for lumber manufacturing at various parameters were also calculated and presented. 5. The effects of some log defects to production cost in yemane lumber manufacturing were quantified and evaluated