Simulation-based evaluation of the ramp-up behavior of waferfabs

Abstract

In this paper we present a simulation study of wafer fab ramp-up scenarios with the simulation software AutoSched AP. A generic factory model (MIMAC 1 from Int. SEMATECH) was adapted to simulate fab ramp-up scenarios. The model was customized to consider time phased modeling capability and time phased reporting. Additionally, an evaluation approach for the comparison of different ramp-up scenarios is presented. This approach helps to evaluate the ramp-up performance with different input parameters. A systematic variation of dispatch rules and lot sizes during ramp-up is shown

Modelling production ramp-up of engineering products

“… "ramp-up is a technical concept and is the period preceding the market production launch" [8]  ramp-up includes the pre-production and the production stages [9]  ramp-up is the "period between completion of development and the full capacity utilisation" [4]  the time from the production of the first item to reach steady-state output rate [3]  the time interval from the end of the prototyping phase to the full volume production [10]  ramp-up is the "initial period of commercial production […] it begins at start of production and finishes when initial targets for, e.g. quality, volume, yield and costs are reached" [11] Authors agree on the steep increase of output rate reported during this phase, but they disagree about the chronological limits of the process.…”

“…Even if production ramp-up and LCs are strongly linked, it is not easy to find examples of practical application of these two concepts. Moreover, the few examples found concern high volume production like semiconductors [10] and assembly [3]. Despite the amount of papers on LC theory and the potential benefits that can derive from more accurate resources plans, there is a lack of literature expressly addressing the forecast of manpower requirements by adopting LC theory [28].…”

Enabling Fast Ramp-Up of Assembly Lines through Context-Mapping of Implicit Operator Knowledge and Machine-Derived Data

“…As ´DataItem´, all entities are considered, which can be read or asked for, but cannot be changed in a direct way. 1 These concepts are modelled in a cross-domain approach which means that they can be related to each of the already presented domains of the static structural model. For explanation a DataItem representing a sensor holds structural information about in which system or module the sensor is installed but also represents an important monitoring variable for a process.…”

“…One possible approach is defining the ramp-up time of products as the "time required from finishing prototyping to full volume production" [1]. However in this paper we are focusing on the ramp-up of new production processes and the resulting problem areas.…”

A Case Study in Scheduling Reentrant Manufacturing Lines: Optimal and Simulation-Based Approaches

“…The first objective of this paper is to present the optimality equations and condition for the scheduling (i.e., job sequencing) of a simple benchmark RML, under an infinite horizon discounted cost (DC) formulation [14], [15] and under general non-negative one-stage cost functions (in the buffer size). In this paper, the DC criterion was selected considering the current dynamics in the semiconductor industry, where costs and benefits in the short-term are important (e.g., during ramp-up of new products [16]) given the short life-cycle of semiconductor devices [17]. Although the RML model presented in this paper is quite simple, the results obtained from this exercise are valuable to study and understand the basic difficulties associated with the synthesis of optimal (or near to optimal) scheduling policies in RML for SMS.…”