Compact or Central Storage System? Which Solution Fits Your Carrier Mix – cts Group Blog
Josef Höving
Josef Höving, cts Group
Manufacturing Automation · · 8 min read

Compact or Central Storage System? Which Solution Fits Your Carrier Mix

The choice of the right automated storage system in SMT manufacturing doesn't depend on available technology, but on what role the storage system should play in the overall material flow: a line-side buffer for a manageable set of material types, or a central supply and circulation hub for multiple lines with high mix dynamics.

The wrong question is: "How much storage do I need?" The right question is: "What role should the storage system play in the material flow?" Once that question is answered, the system decision almost makes itself.

In consulting practice, we often encounter the same starting point: an operation is growing, the carrier mix is becoming more complex, and at some point the status quo is no longer sufficient. The question then becomes: a compact, line-side system – or a central warehouse with more capacity and process structure?

At cts, we don't evaluate this decision based on capacity figures alone. What matters is the role the storage system should play in the overall material flow – and the resulting requirements for throughput, variant mix, returns, and IT integration.


The Systems in Direct Comparison

Criterion cts OCTA Storage cts CUBE Storage
Primary Role Line-side buffer with storage logic Central supply and circulation hub
Suited for Few lines, manageable material mix, clear supply routines Multiple lines, high mix dynamics, many returns and carrier types
Access Times Very short due to line proximity Longer internal paths, compensated by better zone structure
Zone Formation Limited – works well with homogeneous mix Pronounced – clean separation of carrier types, returns, exception cases
Scalability Modularly expandable as OCTA cluster Designed for growth from the outset
Changeover Peaks Buffers manageable peaks More robust with high return dynamics
Footprint Compact, can be positioned close to the line More floor space required, central positioning makes more sense

The Questions That Lead to the Decision

We don't work with gut feeling, but with a brief process and volume assessment. The following questions structure the decision in practice:

Decision Framework: OCTA or CUBE? Based on real project criteria
How many lines need to be supplied – and how frequently is access needed?
Tendency OCTA
Few lines, high replenishment frequency
Short paths and fast access are the primary benefit
Tendency CUBE
Multiple lines, parallel demands
Central supply with process decoupling
How high is the return volume – and how complex are returns and exception cases?
Tendency OCTA
Manageable returns, low exception workload
Standard paths are sufficient
Tendency CUBE
High return volume, many exceptions
Clean zone separation is required
Do reels dominate the carrier mix?
Consider alternative
cts REEL Storage
Specialized for reels: vertical storage, flexible slot management, optional MSD climate zone – makes sense when reels are the dominant bottleneck
Combination possible
REEL Storage + OCTA or CUBE
For the remaining carrier mix
How much will the mix grow over the next few years?
Tendency OCTA
Stable mix, growth clearly plannable
Modularly expandable as OCTA cluster
Tendency CUBE
Strongly growing mix, new carrier types expected
CUBE remains stable where OCTA becomes opaque through additional special rules

Where OCTA Works – and Where It Reaches Its Limits

OCTA Storage works very well when a clearly defined supply area needs to be efficiently organized. Formats and processes must not diverge too much. Limitations arise when many carrier types with very different return and handling logic need to be cleanly separated simultaneously – or when returns and exception cases consume too much floor space and operator time.

⚠ Typical Growth Problem

The difference between OCTA and CUBE usually doesn't show on the first expansion – but on the second or third. When new carrier types are added or the mix grows significantly, an OCTA risks becoming opaque through additional special rules.

Note on CUBE expansion: A physical expansion of the CUBE comes with downtime for reconfiguration and recommissioning. In practice, this is why a future-proof initial sizing with sufficient reserve is preferred. Expansion through an additional storage system is possible at any time – with seamless integration into the existing system landscape, not as a parallel world alongside MES/ERP.

Which Scenarios Point to Which System

cts OCTA Storage

Typical Use Cases

Few lines, manageable material mix, primary benefit in fast handovers and organized returns. High-runner areas or clear supply routines without strong changeover dynamics.

cts CUBE Storage

Typical Use Cases

Multiple lines with high mix dynamics, many returns, and different carrier types. Or: deliberate setup of a central hub for storage, buffer, and return flow.

cts REEL Storage

Focused Alternative for Reels

Vertical storage, flexible slot management without rigid size constraints, optional MSD climate zone. Particularly useful when reels are the dominant bottleneck and no universal warehouse is needed.

Combination

Hybrid Approach

For reel-heavy SMT manufacturing: REEL Storage as a specialized module plus OCTA or CUBE for the remaining carrier mix. Each module handles the task it was designed for.

IT integration in all variants: MES/ERP remains overarching, and the line software manages identification and consumption. The storage logic – whether OCTA, CUBE, or REEL – is integrated so that later expansion doesn't result in a system break.

Conclusion: The System Decision Follows the Process

Neither OCTA nor CUBE is categorically the better system. The decision follows from the process: what peaks occur? How often is access needed? How much return volume is generated? Where do search times and stoppages arise? What protection requirements apply? Anyone who answers these questions soberly gets a clear answer – whether a compact line-side system is sufficient, whether a central flow hub is necessary, or whether a combination delivers the best balance of benefit, effort, and scalability.

Which System Fits Your Operation?

We analyze peaks, carrier mix, return volume, and protection requirements – and show which solution has the greatest leverage.

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