Method to Compute Productivity Metrics for Complex Print Jobs
Publication Date: 2005-Oct-03
The IP.com Prior Art Database
The productivity of a complex print job, for example composed of sets of intermixed simplex and duplex, varies with both the number of sets and each set's delivery face orientation. This variation has been difficult to capture in a formula, often making brute-force scheduling of the job the only way to compute a productivity metric.
The productivity of a complex print job, for example composed of sets of intermixed simplex and duplex, varies with both the number of sets and each set’s delivery face orientation. This variation has been difficult to capture in a formula, often making brute-force scheduling of the job the only way to compute a productivity metric.
The invention is a method that generates a function computing the productivity of print engine jobs which are sequences of a given set. The method consists of scheduling the set a finite number of times and collecting productivity metrics at each step. It is based on the periodic pattern of resource utilization by the print engine as it executes a job and applies to any scheduling method that operates consistently on that pattern.
The method applies to print jobs that are sequences of a given set. The set is described in terms of the component media, sheet and set face orientation, sides-imaged, etc. The method generates a function that computes the job productivity for any number of component sets.
Before performing the steps below, determine the maximum of the duplex spans from the start of first photoreceptor pitch to start of the second. Define the reachback of a photoreceptor schedule to be the latest period of this duration in the schedule. The reachback is the longest portion of an existing schedule that can be affected by scheduling the next sheet.
Step I (execute once per set).
Repeatedly schedule the set, noting the reachback schedule and associated productivity measurements (the reachback schedule is the schedule in the reachback prior to scheduling the capability). Stop after scheduling from a reachback that has been seen before (this will happen because the reachback and number of set capabilities is finite).
Step 2 (execute for any set count).
The data collected in Step 1 is a sequence of pairs of reachback schedules and measurements (r1, m1),…,(m, mn), where m = rk for some k < n. Thus (rk, mk),…, (m-l, mn-I) defines a scheduling cycle. Let productivity(i1,…,i2) be a function computing the combined productivity between Step 1 iterations 1 and i2 (its value is 0 if i1 > i2). The productivity of a job consisting of t repetitions of the set is then:
productivity(l ..t) if t < k;
productivity(1..k-l) + nCycles*productivity(k..n-1) + productivity(k..k+j-1) otherwise, where nCycles equals (t-k)I(n-k)...